Raghu,
For Quant, you will need to know which topic you are weak in and then read the material on the net. For eg: if you are weak in P and C or inequality Google these topics and get the basics right. There is enough on the net. I dont think you need to do anymore. Just search. Once you get your concepts make handful of notes. Kill_GMAT has given us a few links and you can check them out in his debrief.
In RC just one question: After your read the passage, first line last line, or anything are you able to summarise the passage. Try this excercise. Read the passage and then close the computer and ask yourself " What was the passage all about"
If you can answer this question you will do well in the passage. If you cant answer this question that means you have read passively and you do not know the content. If you do not know the content you will not be able to improve in RCs.
Try to summarize the passage and I am sure you will be at 70% accuracy rate in 3 days.
Try Gin's notes.
Let us know how this goes.