If you're not already a subscribee (is that even a word?) with Tim Grey, I strongly recommend it. Just go to his page, and enter your email address.
Ask Tim Grey
He sends free daily emails with various post-processing tidbits. I've been getting them for a few years, and they never fail to be fantastic. Always worth reading.
Each daily email invariably contains a plug for his training DVDs, but please don't let the advertising aspect put you off - these are comprehensive, detailed answers to real digital imaging questions. He really knows his stuff.
There is also an option for a paid membership, which gives you extra privileges. I'm too much of a tightass for that, but the free membership is excellent all the same.