Good questions.
As a general rule, do a chapter at a time, but if you'd like, you can then move to a different book. You don't have to do all of the chapters in a book at once.
I recommend doing some quant and some verbal each week.
This is the order in which we do the quant books in class:
FDP
Algebra
Word Problems
Geometry
Number Properties
But you can adjust that based on your own strengths and weaknesses. If I were you, I'd take a practice test first. Use that to get a good handle on your strengths and weaknesses and you can set your study accordingly. Start with the areas of biggest weakness but, when you're feeling burned out mentally, then spend some time working on your strengths. :)
For the verbal side, you can just go in the same order that the chapters are presented in each book. I'd recommend doing some in one book, then moving to another, etc. It's harder to do all grammar, and then all CR, and so on.
When you finish a chapter, do some of the problems at the end of it (our problems, not the OG problems yet). When you feel pretty good about those, go ahead and try a couple of OG problems (see the lists at the back of each book).
Don't do ALL of the OG problems, though. Do more chapters, then start doing problem sets where you mix problems from multiple chapters. Mix up DS and PS. Mix up CR, RC, and SC. Mix up quant questions across the 5 books. The real test will give you everything mixed together, so do that yourself as you study.
Take a look at this article for more:
http://www.manhattangmat.com/blog/index ... an-part-1/Good luck!