Limewire sucks dong for viruses. I think you should give a torrent program a try, if you don't like what you see stick with itunes.
With a torrent downloader you can read reviews and people will tell you if it's infected before you try it, you can usually tell by how many seeders there are. If it has no reviews, don't d/l it!
You just have to know what to download, if you don't your fucked.