Blogs are great. They help you keep in touch with friends and let the world know your thoughts. Which is all well and good, but you have to make sure you're sensible about it. What you think may be a harmless piece of information, like the school you're from or the local football team you play for, could be all someone needs to be able to trace you in real life. You know all the horror stories - just take care in the details you're posting and think before you click "Submit".

We seem to live in a world where everything has a password - your bank account PIN, e-mail accounts, mobile phone codes... the thing is, all too many people use the same password for everything online. That's their e-mail account, their blogging login, instant messaging programs, and whatever else they get up to. Don't be one of these people - use different passwords for different activities to make sure you're safe if someone finds out. It's a good idea to use a combination of letters and numbers for extra safety, change it regularly, and make it something less obvious than your dog's name. Apparently that's the most common password chosen.

Sometimes it seems a mystery how spammers got hold of your address in the first place. Often, they send what's called a spider out, which crawls web pages looking for e-mail addresses. So, if you've got your e-mail posted on somebody's Guestbook or on your own personal website, it might be the source of some of the spam. There's one easy way you can protect yourself here - disguise your e-mail address when you post it online. Humans will be able to interpret it correctly, but spiders won't. Here's some examples:

rob@~deletethis~email.com
rob [at] email [dot] com
rob@ *SPAM* email.com

You might think it makes sense to click the “Unsubscribe” link at the bottom of Spam e-mails. But think of it this way: if these spammers are willing to send you advertisements without your consent, are they really going to care if you ask them not to? In truth, clicking Unsubscribe merely confirms that your e-mail address is a valid one. Most web-based e-mail clients allow you to click a "Report Spam" button that will move the offending message into your junk mail folder. Doing this will also train the spam filters to reject this kind of message in the future. If you don't have this feature, simply delete the message.

One of the best things about the Internet is that there are so many sites where you can get free e-mail accounts. So…take advantage of this. If you keep getting spam, make another e-mail account just for your close friends, and don't give it out online. Have another one for your instant messaging programs. And maybe even another for any online newsletters you want to sign up for.

MSN Hotmail
Gmail
Yahoo Mail

If you're using file sharing software to download music or movies, you'll probably have come across files that aren't named correctly or contain different material to that which you were expecting. Most programs have a ratings or comments system whereby other users who have downloaded the same file can report on whether it was what they were expecting. It's a good idea to check this before you start downloading… and to participate in the system to help other users, too.

If you want to stay on the right side of the law, there's a number of legal music downloading sites that are still compatible with your MP3 players and allow you to enjoy music without fear of being prosecuted. All the different services available have different terms - for example, some give you unlimited access to the music you purchase, whereas others limit the number of compilation CDs you can make with it. Some let you pay per track, whereas others charge a monthly fee. It's a good idea to look around the market and see what suits you.

MSN Music Store
iTunes Music Store
Napster

If you've accidentally come across material online that's illegal - child pornography, for example - it's important to report it to the correct authorities so it can be dealt with. The Internet Watch Foundation has been set up to allow you to report any illegal content you have encountered.

If you're accessing the Internet through a wireless network in your house, be sure to check that encryption is enabled. If it isn't, anyone could stand outside your house with a laptop and start viewing your files. And even if they couldn't do that, they'd still be stealing your Internet bandwidth. Check with whoever set up the network in your house as this is vitally important.

Without proper protection from viruses, you're leaving your computer at risk from all manner of threats. Thankfully, there are a number of free anti-virus programs out there to regularly scan your computer, and if you keep it updated, you should be safe from the newest viruses. AVG by Grisoft is widely used and regularly updated to catch the newest viruses. And for a quick check, Trend Micro have produced Housecall, a virus scanner you can run straight from your web browser.

Grisoft AVG Free
Housecall

If you use the Internet regularly, it's worthwhile having some anti-spyware software installed. They work by scanning your system for known spyware and adware components, and letting you delete them if any are found. You can even schedule the software to scan while you're sleeping. Microsoft's recent beta release of Windows Defender is receiving great reviews, with both Lavasoft AdAware and Spybot Search & Destroy also being well-respected. As with your anti-virus software, you need to make sure you keep anti-spyware programs updated regularly - most programs clearly show how to do this in their help files.

Windows Defender
AdAware
Spybot Search & Destroy

A firewall is a buffer between your computer and the Internet. It limits both incoming and outgoing information, and keeps your computer safe from intruders. It can't stop you downloading spyware, but it can alert you if a program is sending information over the Internet without your permission.

Both Windows XP and Mac OS X include excellent built-in Firewalls, and it’s a good idea to keep them on at all times. Click the following links to find instructions for your OS:

Windows XP
Mac OS X

If you need a little more control, third-party firewalls might be your best bet. Zonelabs produces ZoneAlarm, a free firewall for Windows with an excellent reputation. For Macs, there are no known free firewalls but Norton Personal Firewall is a recommended commercial product.

Internet Explorer (Windows) and Safari (Mac) aren't your only choices when it comes to searching on the web. In fact, many technical professionals are now suggesting you look at some of the new browsers available as they could help in preventing spyware from reaching your PC. Mozilla Firefox is gaining popularity at the moment, as is Opera. Both deserve a look.

Mozilla Firefox
Opera

There's nothing worse than being greeted with an ad for an online casino when all you're looking for is song lyrics. The latest versions of both Internet Explorer and Mozilla Firefox both include blockers that detect when a popup is being loaded without you asking for it. This should be enabled by default but all the options are easily accessible from your browser's settings menu. Several browser toolbars now exist that also include popup blockers, such as the Google Toolbar.

It's all too easy to rush through installation screens when you want to download the latest track from your favourite artist, but you need to make sure you're not sharing more files than you thought. When you're installing the software, read each screen before clicking Next to make sure you're not accidentally sharing half your hard drive to the outside world. Every so often, check in the options of your file sharing program to make sure you know exactly what's being shared and what's not.