Couple things I've seen in the blogsphere the last few weeks that I wanted to point out:
Advanced SharePoint Services Solutions: This book was published a while back, but it actually looks like it's worth it's money compared to just about every other one out there. It has a chapter on extending search and one on MCMS integrated solutions. The free chapter was VERY good... when I roll off this project, think I'm going to visit my local bookstore to thumb through the MCMS chapter to see if it's worth buying. I'm very hesitant to buy a MCMS/SharePoint book as most of the ones I've seen aren't for really advanced audiences.
SharePoint tools: These aren't all specific to SharePoint, but it's things I use quite often (via Mark Harrison & Eric Schoonover):
One of my favorites: Fiddler.