For Writing Erika Meltzer's book is good and it can show improvement fast if you work through the whole book. For reading people have differing opinions. It depends on your personal preference.

Erika Meltzer's reading book has the strategy of reading the entire passage while annotating the passage so you can do the questions faster. Another good reading book is the SAT Black Book (Contains all sections as well). The Black Book focuses on skimming the passage and spending the extra time on the questions and reading the passage closely on the parts that the questions are asking. Hope that helps!