Most important - make sure that you're using a good AV (antivirus) program. Keep it updated & scan all files that you download with your AV, before you open them.

A few links below to help... also check the sticky threads at the top of each forum section - they have lots of info

Virus thread: Typical virus spam file sizes - Make a note of them (click on blue link to see)

* WARNING: Viruses on network you should be aware of ! *

Fake files showing up in search results

How to use Bitzi

How to find music