There is no such book for preparation of writing section (AWA) for GRE. To prepare for this, you must practive englisg allday, everyday. Try to use english language in your daily conversations. Watch hollywood TV shows, learn new words, watch english news channels. Also, try to write atleast an article with 300-400 words everyday. learn the correct use of punctuation marks, exclamatory signs, aspostrophe etc.
I suggest you to refer to the ETS' official guide for instructions and tips on how to go about in the AWA section. AWA basically has two parts:
- Analyze an issue
- Analyze an argument
There is a pool of around 150 topics given on the ETS website. The tasks will be from those topics only. Nothing outside that. So if you get time, you can go through the various topics and try to formulate points,atleast for the ones that you think you may not be able to write well on,directly on test day. Because it won't be possible to go through all 150 topics.
All The Best.