If you have an iPhone or Mac, check out VoiceOver, it comes as part of the platform.
http://webaim.org/articles/voiceover/ has a pretty good intro to VoiceOver on the Mac.
I'm on windows, and personally use the free and open source NVDA screen reader http://nvaccess.org
Once again it looks like WebAIM have some good instructions to get you started: http://webaim.org/articles/nvda/