(Microsoft has Narrator, but it doesn't have all the desired features.) VoiceOver can be toggled on and off with Command + F5. This is different than most PC screen readers, which are third party applications. VoiceOver, the Apple screen reader, comes pre-installed on all iOS devices and Mac computers. I am using a MacBook Air running Mac OS X Mountain Lion. There are some similarities between Mac and Windows commands, which can make the transition from PC to Mac a bit easier.
This article will discuss how to accomplish these tasks on a Mac. As with any screen reader, VoiceOver has its own set of commands for accomplishing specific tasks, such as editing text, reading documents, and finding specific words.