Here are some very useful add-ons for Mozilla Firefox that will keep you safe from malicious content on the web:

Adblock Plus - will keep annoying advertising out of your site; allows custom removal of ads as well. Enjoy surfing without ads

WOT - Knows as Web of Trust, gives you rating for each site you visit. Ratings are based on WOT users' evaluation of that particular site. Quite simple and effective to get basci onfo about a site.

BetterPrivacy - Website owners and corporations won't stop finding new ways to get more info on how you use the web. A new way of doing so is to use "super cookies" that are not deleted by the browser. These remain in your system and spy on you. This add-on will remove them whenever you close you Firefox.

If you are successfully using any other add-ons for Mozilla Firefox, please share them with us!

MrUnknown