Also on Linux you should check out RawTherapee. Or if you are willing to shell out some money Bibble Pro 5 is supposed to be excellent (although I've never tried it).
I find that I shoot jpg for everything unless I'm doing a "shoot" (portraits, event, etc). When I'm just taking pictures for myself, it's always jpg.
Oh, wow... I just looked up DuChemin's book (here for anybody else who cares), and it looks astounding. You're right, it seems more about working with and improving individual photos than setting up Lightroom as an "uber-library". The first review says "Five star plus, if you're ready for it." I'm probably not (yet), but I've added it to my wish list for when I am.
The Luminous Landscape videos look great; 52 ten-minute videos covering all aspects. I'll probably go that route; I do so much work-related technical reading that it'd be a nice change to watch a lesson.
You'd be surprised about face-recognition, Picasa does a fantastic job, and it gets better as it learns more. I just can't stand Picasa's interface.
Both face-tagging and geo-tagging aren't strictly necessary of course, but neither are date/time stamps. I find myself annoyed when I go back through older digital photos that were taken with a crappy point-and-shoot where the unreliable internal clock has tagged all photos as "2005-01-01 00:00:00". I can guess as to when the photos were taken, but looking back, I'd rather have real date information. I have a feeling that in the future I'll probably feel the same way about geotagging. Especially for nature shots. There are some photos I took of a hidden waterfall and lagoon on Maui that I probably couldn't find again if my life depended on it. GPS coordinates embedded into the photo would have been nice. :-)