Online shopping is now enormously popular, with retailer Amazon and auction website eBay currently ranking highly in the 10 most visited websites both in the UK and the US. Low overheads and the sheer number of online traders looking to attract your custom mean that prices are extremely competitive, and handy tools such as price comparison websites make it easier than ever to find the cheapest deals.

In this feature we'll be looking at all aspects of shopping on the web, including how to find the best online retailers, where to track down the cheapest prices and save hundreds of pounds a year, and how to shop safely and with confidence.

It pays to browse
Any wise buyer will tell you to shop around before you even think about parting with your hard-earned money. There are bargains to be had everywhere and it's usually just a question of knowing where to look. The internet takes this shopping philosophy to extremes and offers far more in the way of bargains than any small-scale price war between local retailers will.

Instead, you can compare the cost of the same product at hundreds of different websites from across the country and, in some cases, from all around the world.

Let's take, for example, the latest Lord of the Rings DVD, The Return of the King. The suggested retail price for the two-disc set is around £26, but visit your nearest HMV store and you can expect to pay about £20 for it. Before making the trip, however, it's worth checking the prices offered at a few online stores first; you might be surprised by just how much you could save.

At the time of going to press Amazon was listing this DVD for less than £15 (plus postage and packing), while Play.com was selling the DVD for £16 with postage included.

Buying from abroad

Occasionally, it can even be worthwhile buying from abroad. In the case of DVDs some films include extra features not found on the UK version, benefit from earlier release dates or occasionally work out cheaper if bought from an international retailer.

Bear in mind that buying products this way brings its own set of costs,charges and considerations. Search for a product at the multi-region DVD Price Check website, for example, and you might discover what appears to be a real bargain or rarity from across the Atlantic. However, remember that international delivery costs will bump up the price considerably.

Also, importing a DVD - and many other types of product - with a value exceeding £18 from countries outside the EU could hit you with additional customs duty, tax and handling charges once they reach UK shores. Check out the HM Customs and Excise information on this particular subject before you buy.

When buying electronic goods, bear in mind that there are different standards (Pal versus NTSC for televisions and camcorders, for example) and voltages to contend with.

Be wary of some of the really cheap electronic products listed on some price comparison sites, too: a few unethical online vendors make a living from reselling cheap, imported products and you could find that they don't come with the right mains adaptors or that the foreign warranty might not be honoured by the UK arm of the manufacturer.

If you unknowingly purchase such an item you should return it to the vendor and demand a refund. If you are having general problems with goods purchased from a foreign website,have a look at the Office of Fair Trading's guidelines for shopping from abroad.

Compare and contrast
Of course, there are few things more galling than forking out £20 for something only to find the same item two shops down the road for £5 less. So how do you make sure you always find the best deals when faced with legions of retailers online?

If you shop for certain items regularly - let's take DIY or gardening products as an example - you might want to bookmark a few similar vendors' websites, such as B&Q, Screwfix, Crocus or Greenfingers. Once that's done you can run a quick search for the product you're after at each of them before you decide which one to go for.

It's certainly easier to compare prices this way than having to traipse from shop to shop. But if you don't know which websites to check you might be missing out on some of the best deals without even knowing it. Thankfully, help is at hand in the shape of dedicated price comparison sites that scour the web for you in search of rock bottom prices.

While some of the original price comparison sites, such as ShopSmart, have fallen by the wayside, many are still flourishing. Kelkoo and Pricerunner are two fine examples. Both are cleanly designed and easy to navigate. You can browse through familiar virtual aisles, including Household Appliances, Health & Beauty, Electronics and the like, or simply type a product name, brand or model number into the search box and hit return.

The resulting list of deals can usually then be sorted by price or alphabetically by vendor. For example, our search for a Fuji FinePix F700 digital camera at Kelkoo turned up 19 different prices from various outlets, ranging from just £239 on eBuyer to the most expensive, £430 from Argos.

For price comparisons on computer equipment, software, peripherals and other electronics products, you should try using Computeractive's own Active Prices service.

It's in the post
When you're comparing deals at various websites, remember that it's not just the prices of the products themselves you need to consider. Take our earlier example of The Return of the King. At Amazon the DVD was on sale for under £15, but factor in delivery costs and the total price goes up to over £16, which makes the total cost of the DVD more than it would be at Amazon's competitor, Play.com.

If you use a price comparison site, you can usually check the 'total price' column for a truer idea of how each vendor's charges really match up. Many retailers offer a range of delivery options and it is often cheaper to buy in bulk.

Unless you're in a desperate rush to receive the goods you have ordered, it's also usually cheaper to select the slowest delivery option. If, for example, you purchased The Return of the King from Amazon along with other goods totalling more than £25, you would qualify for the retailer's Super Saver Delivery, which is a free-of-charge delivery service, although the products could take slightly longer to arrive (three to five days, according to Amazon).

In terms of delivery, it's not just the cost that you have to watch out for; the convenience factor is also important. When buying small products (books, CDs, DVDs), this isn't really a problem as they usually get popped through your letterbox by your postie. Some online retailers use courier services but, once again, this isn't too problematic, as re-delivery can be arranged should you happen to be out when the van arrives.

Perishables, such as your weekly grocery haul, or larger goods such as fridges and sofas, will usually be delivered by the retailer itself, and this is where you might start experiencing problems. Thankfully, most supermarkets have cottoned on to the fact that shoppers aren't able to wait around all day for a drop-off. Nowadays grocery retailers such as Sainsbury's and Tesco provide their customers with convenient two-hour or three-hour delivery slots.

Unfortunately, some retailers still think it acceptable to give their customers the very vaguest of delivery promises, so it is worth checking the delivery small print before you place an order.

Think before you buy
There are a few other issues you should consider before you make your final choice of internet retailer. Does the site you are planning to place an order with offer a secure credit card payment facility? How quickly does it dispatch products? Does it let you know whether a product is in stock or could you find yourself waiting up to 28 days for the goods to arrive at the warehouse before they are even dispatched? What if the goods are faulty or turn out to be unsuitable upon delivery? Does the site offer an acceptable level of customer service?

It is definitely worth reading each retailer's About Us page, along with any terms and conditions and returns and delivery policies that are available. It's also a good idea to check that a more traditional means of contact, such as a phone number or mailing address, is provided somewhere on the site, for peace of mind. Most price comparison websites provide information pages on the vendors included in product searches, which will at least arm you with a mailing address and telephone number.

You should also find other valuable information on aspects such as returns policies, delivery costs and payment options. If you want to check independent reviews of various online retailers, written by consumers based on their own shopping experiences, then head to Dooyoo. While the site is a little too liberal with its use of pop-up ads, there's plenty here to help assess the general trustworthiness of an online vendor. And while you're at it, check to see if the site features any customer reviews of the actual products you're planning to purchase or make use of its impartial price checker.

Safe as houses
If you haven't yet taken advantage of online shopping, it's likely that your reasons for holding back are at least partly based on concerns about using your credit card on the internet.

With all the scams and scandals around at the moment, such as phishing and identity theft, it's understandable to feel reluctant about entering sensitive details on a website. Despite all the scare stories in the media, however, sensible shopping online is just as safe as buying goods over the counter.