I always rave about EarnersBlog.com. This is one of the FEW blogs that has nearly ALL worthy posts. Most blogs about PPC/Adwords/Google are almost ALL fluff. Earners blog posts only once or twice a week, but they are awesome posts.
Check out this one on how to explode your ppc campaigns.
If you’re lazy, the best parts of the post that I liked are to “only go after phrases with 3 keywords or more”. Less than 3 and you’ll get a lock of lookers, but very few converters. Also “don’t use broad terms” unless you are doing keyword research. Only use Phrase and Exact. For example “RINGTONES” converts less than “DOWNLOAD RINGTONES” which converts less than “HOW TO DOWNLOAD RINGTONES”.