Know-How Exchange : E-Marketing

I've used Overture PPC advertising very successfully in the past, although I know Google gets more traffic and many people prefer it. I'm looking for a good resource for understanding Adwords pricing and bidding process.

Overture shows exactly what the top bidders are paying which lets me figure out how much to bid max for position. Overture also shows historical traffic levels on phrases, so I can approximate total spend. Google seems more cryptic -- pick a max bid out of the air and you really have no way of knowing how much you'll pay or what traffic will be. How do you determine the right amount to bid? Is there any way to tell how much others are bidding? How exactly does click rate affect your actual bid? I know higher CTR lowers the required bid, but what's the formula (i.e. double the CTR pays half?)?

Would appreciate any advice on Adwords basics, particularly on campaign planning, price setting, campaign management best practices, etc. Any good websites or books you can recommend? Looking for real meat, not a high level overview.

Thanks much,

Alex