We'd be happy to help but we need a LOT more information from you.
What materials / resources do you have right now? What have you already studied?
You asked for a math workbook - we have lots of books, but I don't know what your strengths and weaknesses are, so I don't know which ones you need. Use the below article to analyze your most recent practice test:
http://www.manhattangmat.com/blog/index ... ice-tests/Then come back here and share your analysis. (Note: not just the raw data - tell us what you think it means.) That will give us some good data with which we can advise you.
If you discover you have any timing problems, read the below article and start doing what it says:
http://www.manhattangmat.com/blog/index ... anagement/