I am using Mozilla Firefox browser since it's inception. I love that browser. The tab concept is beautiful. It's fast and interface is good. One thing that makes Firefox more useful is you can use extensions for different purposes. Once, you install firefox, go to Extensions area and download the extensions you want. I found the following extensions very helpful.
1. Adblock: This extension blocks not only the ads but any element on the web page that you don't want the browser to display to. It effectively blocks all advertisements. Once you install the extension, you can import filters, which are available online. I found the filters at the following place very good. [ http://www.geocities.com/pierceive/adblock ] Check the list of the filters before you import. You can remove those filters later, if you don't want to.

Following are the extensions I have for my Firefox:

Extensions (enabled: 24, disabled: 0)

• Tabbrowser Preferences 1.2.4
• Adblock 0.5.2.039
• ForecastFox 0.7.1
• ieview 0.87
• Download Manager Tweak 0.6.5
• Web Developer 0.9.3
• PDF Download 0.2.5
• User Agent Switcher 0.6.5
• whois 0.22
• Sage 1.3.1
• QuickNote 0.6.0.1
• CuteMenus 0.4
• Html Validator (based on Tidy) 0.5.9
• SpoofStick 1.05
• FirefoxView 0.31.1
• ViewSourceWith 0.0.6
• Feedview 0.9.7
• Paste and Go 0.4.1
• Print It! 0.3.1
• jsLib Lite 0.1.278
• Mozilla Archive Format 0.4.3
• InfoLister 0.8.2
• TargetAlert 0.7.4
• downTHEMall! 0.9.4