The most powerful and popular search engine for some years now has been Google (www.google.com), and I recommend using this as your first-choice search engine. At a basic level it is very easy to use -- just enter the word or words you are looking for in the search box and click on 'Google Search'. If you are searching for a particular person, enter his or her name within double inverted commas, as below:

"James Philip Swindler"

Putting the name in double inverted commas ensures that only web pages including this exact term will be listed. If you don't use the inverted commas, Google will list all websites including the words James, Philip and Swindler anywhere on the page. Using the double inverted commas therefore helps narrow the search down.

Suppose though you're looking for someone with a very common name -- John White, for example. Even if you put this in inverted commas, Google will still come up with a lot of references (over 1,600,000 when I just tried). Many of these will refer to other John Whites, so you will need to find some way of narrowing the field. One way of doing this is to add further search terms. For example, if your man was last heard of in Belfast, you could try entering the following in Google:

"John White" +Belfast

This will generate a list of all pages including the terms "John White" and Belfast. The use of the + sign in front of Belfast is optional, but ensures that only pages that also include the word Belfast are listed. Similarly, if you know that John White once worked for the company Motorola, you could enter the following:

"John White" +Motorola

Or you could combine the two:

"John White" +Belfast +Motorola

Finally, you can use a minus sign (hyphen on the keyboard) to exclude certain pages. For example, let's say you're looking for someone called John Major, but you don't want the former British Prime Minister. Enter the following in the Google search box:

"John Major" -"Prime Minister"

Only pages that include the name John Major but exclude the term Prime Minister will be listed.

The above is a very basic guide to using special characters to help narrow down a search. There are many other things you can try as well, and clicking on Advanced Search on the right of the Google search box will reveal these to you, along with tips on how best to use them. You can, for example, set Google to display only web pages that are written in a certain language or on a particular domain (for example, .com). Much of the time, however, using just plus and minus signs and double inverted commas will be sufficient to narrow down the search.