Digiartists' Domain Community!

Now I am not sure if this is the right place to post this but it seemed close enough. Due to past experiences I have become slightly paranoid about clicking on site links, especially ones that have specifically sexual material. My question is thus, does anyone know of a site or program or something that can go to a site and then tell you if it would download any harmful programs without you realizing it.

Failing that I would like to know how all of you go about visiting sites and determining if they have viruses and such while keeping your computer safe.

Well, Firefox often times blocks access to sites it thinks has something. And my Avast! software often times blocks all viruses too.