Danny Sullivan is one of the most respected, sane, and comprehensible experts out there on how the web, web traffic, and search engines work. He talks to people at Google every week, so he often has insider info.
I recommend the "Easy Links, not Hard Links" article especially.
Lately, a lot of Danny's articles have been covering letters that Google has been sending out warning big sites when they're using shady linking practices that Google considers fishy. While most of us don't have the time or budget to engage in these practices on the large scale that tends to trip Google warnings, it's good to learn what practices work, and what are a waste of time (or possibly harmful, if done too often.)