Nova's GRE Prep Course provides the equivalent of a 50-hour 2-month course. This comprehensive test prep book provides twenty-two chapters of review material and hundreds of GRE-style practice problems and examples. Plus we'll take you inside the heads of test question writers to help you understand and outsmart the GRE question mentality. 
Key features
Math: Twenty-two chapters provide comprehensive review of GRE math.
Verbal: Develop the ability to spot places from which questions are likely to be drawn as you read a passage (pivotal words counter-premises etc.). Also learn the 4000 essential GRE words.
Writing: Comprehensive analysis of the writing task including writing techniques punctuation grammar rhetoric and style.
Mentor Exercises: These exercises provide hints insight and partial solutions to ease your transition from seeing GRE problems solved to solving them on your own.
Dual Exercises: These are pairs of similar GRE problems in which only one property is different. They give you insight into how GRE problems are constructed.
Detailed solutions to hundreds of GRE questions!
Software:
In Mentor Mode you are immediately told whether you answered the problem correctly and you can view a solution of the problem
In Test Mode you can take a test timed and scored by the program