My experience-

Keep repeating the reading of Barons GRE for verbal. It is more than enough to get 500+ (I took it in 2005, got very easily 500+ without much effort, I used just Barons GRE Book for the preparation)

I did not score well in GRE writing part though (may be my computer typing skill was not good, may be I made alot of mistake in typing, at that time there was no option for writing on paper). In Toefl I got 5.5 out of 6 in writing part. I wrote the essay with pencil on  paper while taking Toefl.   

Since you are short on time, try Princeton Review's 'Crackin the GMAT'. This book has some nifty tricks on how to tackle most common GMAT questions (especially the verbal section). Good Luck!!

Barron's good source for vocab. Memorize as much as u can. U need a lot of reading and repitition and putting into sentence structure helps to retain that in ur longterm memory.practice reading comprehension, analogy ,sentence completion and antonym as well. Bigbook is the great source for verbal if ur target is 500+.

For Analytical writing go into the GRE issue and argument topic pools and practice them.pick 20-30 each.

Remember-Gre cant be mastered but it can be beaten.  To achieve better score u need to devote more time.I would recommend to devote more time unless ur genius.

When writing essay write outlines first, then put them into intro, 3-4 body paragraphs and conclusion.As we know we spend the least time on analytical we should spend a little more to make it worth.