Screen readers:
A screen reader provides access to browsers and web sites for users with Visual Disabilities by reading information on the screen aloud. The following is a short list screen reader options for web developers to consider.
If you are interested in hearing your site read try Webanywhere – an online screen reader. If you are looking to test your site(s) and meet accessibility standards then try NVDA.
JAWS®: http://www.freedomscientific.com/products/fs/jaws-product-page.asp
Industry Standard.
"JAWS®, the world’s most popular screen reader. Developed for computer users whose vision loss prevents them from seeing screen content, JAWS reads aloud what’s on the PC screen."
With a price of around $1,000 JAWS® is the industry standard screen reader. Most likely your Visually Disabled visitors will be using this software. Web developers, however, are not used to paying for testing tools and will immediately begin searching for alternatives.
A comparable tool is Window-Eyes.
Webanywhere: http://webanywhere.cs.washington.edu/
Online. Zero install.
"WebAnywhere is a web-based screen reader for the web. It requires no special software to be installed on the client machine and, therefore, enables blind people to access the web from any computer they happen to have access to that has a sound card."
This is a great way to get started and to get an idea of what it sounds like. However, if you are going to be doing much testing you will want a screen reader utility that lets you change preferences such as voice speed.
NVDA: http://www.nvda-project.org
Recommend.
"NonVisual Desktop Access (NVDA) is a free and open source screen reader for the Microsoft Windows operating system. Providing feedback via synthetic speech and Braille, it enables blind or vision impaired people to access computers running Windows for no more cost than a sighted person. Major features include support for over 20 languages and the ability to run entirely from a USB drive with no installation."
NVDA can be installed but also comes as a portable app and provides the ability to adjust preferences to your liking. I recommend getting started with this tool. It is the sweet-spot option of free and feature packed.
Comparable tools are VoiceOver and SystemAccess.
Fangs: https://addons.mozilla.org/en-US/firefox/addon/fangs-screen-reader-emulator/
Firefox plugin.
"Fangs renders a text version of a web page similar to how a screen reader would read it. The ambition is to help developers understand how an assistive device would present a website and thereby increase chances of finding accessibility issues early."
Once you know how a screen reader works then Fangs is a quick way to check how screen readers will read your site.