Hi jcallahan6,

Before you concentrate too much on trying to learn all of those little rules, you have to make sure that you are comfortable with all of the basic rules, formulas, patterns, etc. If you're not quite to that level yet, then I'd suggest spending some time at Khan Academy. It's a free site that will teach you all of the essentials to Algebra, Arithmetic, Geometry, etc. that you'll need for the Quant section of the GMAT.

Most Quant questions can be solved in a variety of ways, but most books won't show you all of the options. The little rules, patterns, etc. that exist behind "math" are best learned by "doing" (as opposed to reading a big list of rules and trying to memorize them in bulk), but seeing them presented by experts is also a great way to learn the rules. I suggest that you spend some time in these Forums, reading the responses to the various questions that other users post (and you can post some too, if you'd like). You'll come to find lots of little tips. Digesting them in small chunks and seeing them used against GMAT questions should help you to gain "context" for the rules (e.g. when to think about using them and how to use them).

GMAT assassins aren't born, they're made,
Rich

It sounds like you need a betting grounding in the foundational principles of math. MGMAT offers Foundations of Math workshops, a Foundations of Math strategy guide, and dozens of drill sets to help you:
https://www.manhattangmat.com/Programs/Workshops
https://www.manhattangmat.com/storeitems ... 1&catid=10