Being hacked is not something that only happens to others.Some basic tips:
* Don't buy from gold sellers and power levelers.
* Don't share your account info with anyone.
* Don't download from shady sources.
* Do keep your anti-virus/anti-spyware tools up to date.
* Do change your password regularly.
More in-depth tips:
* Get a virus scanner. Grisoft provides one for free. Be sure to configure it to scan your system regularly and to check for updates. (Even the best anti-virus software won't do you any good if it doesn't know about the latest virus information -- so keep it updated!)
* Get a free anti-spyware program and run it. Spy Sweeper is a good one. As with your anti-virus software, be sure to configure it to scan your system regularly and check for updates.
* Install firewall software that prevents any unauthorized access between your computer and the Internet. Comodo is recommended. Again, its free and well regarded.
* Be sure to run the latest version of your browser software. Whether it's Internet Explorer or Firefox, keep it patched and up to date! Many exploits that hackers used have already been patched by the software vendors -- all you have to do is stay updated!
* On the subject of browsers, consider using Firefox. There's plenty of room for debate on whether it's more secure than Internet Explorer, but for now, at least, there are more viruses and exploits out there that target Internet Explorer, simply because it's more widely-used.
* Keep your OS up to date. Just like with browsers, many hackers will try to install keyloggers on your system using exploits that have long since been patched by the software vendor. If you run Windows, be sure to run Windows Update regularly -- in fact, I recommend setting it up to run automatically on a daily basis.
* Be careful downloading files! While your anti-virus and anti-spyware software should catch anything that gets installed, it's better to catch them before they get installed and have a chance to cause damage. Never download files from sites you don't trust and be wary of opening unexpected e-mail attachments.
* You can configure your WoW client to remember your user name. In this case, even if you get a keylogger installed, they'll find your password, but won't know your account name. The password is useless without the account name, and if you don't type the account name, a keylogger won't see it.
* And, of course, never share your password. You may just give it to one person, but who knows where it could go from there. (For all you know they've got it on a post-it note on their monitor where anyone can see it.)
More reading:
http://www.wowinsider.com/2007/06/05/how-to-protect-your-system-from-keyloggers/http://www.wowinsider.com/2008/03/17/wow-rookie-account-security-basics/http://www.wowinsider.com/category/account-security/