There are so many books and softwares out there for the GRE test preparation.I would recommened some of them.

GRE Barrons:

This is the ultimate source for the preparation. The wordlist provided in this book provide a great oppurtunity to improve your vocab power. Even the Quant given in this book is of good one to brush your concepts.But, do some extra practise.Dont forget to do practise tests in this book.They say ,these are quite important.Finally, i would say this book should be read at first.After completing this one switch over to next one.

Kaplan:

This book is also good for preparation. This has a short number of words but they are quite important.I would say more frequent words coming in exam.

BigBook:

This is one hell of a book for practise.I say dont give your exam unless you finish some practise tests in this book. During practising you will find many more interesting new words here.

Internet:

You can get a lot of information here. What ever you want , you will find it here.I say read a lot to improve reading and understanding ability so that you perform well in your reading comprehension section. If you get aware of different types of topics like history, psychology, technology, revolutions, literature ... many more it will be quite useful while writing exam as you can have a rough idea of the passage given there. You can do as many as online tests here.

There are many practise tests available.( softwares). I would recommend some of them which i found useful.

* Kaplan tests--- difficulty level is good

* Princeton - The tests as well as book is good one.

* 800score tests

* Powerprep

I found these as sufficient.But you may find many more which can be better than them.