The CCH Consumer Credit Guide has charts comparing the state laws regulating credit cards.
Credit card laws are discussed in Clark's The Law of Bank Deposits, Collections, and Credit Cards (A.S. Pratt).
Kiplinger posts online credit card-related calculators that figure things like how much you will save if you get a lower interest rate or whether it's better to get a low interest rate or no monthly fee (www.kiplinger.com/tools).