[Android Software Development] bitbang3r:
(edit: the following assumes you've more or less mastered Java already; I really don't know what to recommend for someone who's trying to learn Java AND Android programming simultaneously. I suspect part of the reason for the lack of books for THAT niche is due to the fact that it's more or less impossible to take any programming class in college that doesn't either involve Java or have it as a non-negotiable prerequisite, even if Java per se isn't directly relevant. It's just part of the baseline cultural background noise).

If you buy nothing else, buy "Beginning Android 2" by Mark Murphy. If you're not totally broke, buy "Pro Android 2" by Sayed Hashimi while you're at it. Don't try to skip the first and go straight to the second... there's a lot of medium-level stuff that's covered thoroughly in "Beginning" that's barely touched upon in "Pro".

Those two books aren't great if you like to jump around and learn things in random order as need arises, but they're probably the gold standard right now for books that comprehensively teach Android Programming in a sensible order from start to finish.

"Professional Android 2 Application Development" by Reto Meier is a great complement to those books, because it IS more of a "jump around and grab important details as the need to learn them arises" book. I refer to all three on a regular basis.

"Hello, Android" is one of those books that you'll probably never look at again two weeks after you first start reading it... but if cash isn't really a problem, it's a nice tutorial for brand new Android developers.

Content-wise, the pdf commonsware.com books by Mark Murphy (yeah, the same Mark Murphy who wrote the Apress book) are probably the best of all, because they literally ARE updated regularly as typos & bugs get found (every book has 'em, few books ever usefully fix 'em) and new versions of Android get released. The problem is, unless you have an ebook reader, let's be honest... ebooks kind of suck. Sometimes, a real book is nice to have. So, I'd say Murphy's books kind of break new ground between online articles and real books... they go into a lot more depth, more coherently, than any one online source of info about Android programming... but unfortunately, because they're ebooks, they're about as pleasant to casually read as those same online articles.

18 months from now, when Android tablets with 1280x720(*) displays or better are common and relatively cheap, eBooks are going to be the norm for Android books going forward, because THEN they'll let you have the best of all worlds -- the coherent editing and comprehensive content of "real" books, the up-to-date accuracy of the best online sources of info, and a reading experience that doesn't kind of suck. Five years from now (when the eBook experience has finally become civilized), I'll be shocked if programming books even exist anymore in printed form, aside from maybe books like "${Language}: How to Program" that deal with topics that don't really change radically from month to month and are more or less universal as college textbooks. Programming and system administration are the kind of topics that are really too volatile for paper books, and for they most part they've ALWAYS been... there just hasn't really been a civilized alternative to them. IMHO, Android tablets will be what finally make it a civilized experience, because for the first time normal people (meaning developers who don't work for huge corporate entities like Amazon and Sony) will be able to develop ebook apps with their own UI experiments. Right now, all we have are devices optimized for reading mass-market top-20 fiction... devices that largely suck for the specific task of reading (and referring to) programming books (where you generally flip around a lot, and 700ms latency every time you change a page will drive you insane in 3 minutes).

So, in summary, here's my recommended buying order:

If cash is abundant and you want a nice intro: Hello, Android (latest edition)

Absolutely mandatory: Beginning Android 2

Equally mandatory, but maybe a few weeks later: Pro Android 2

then, it's a toss-up between a commonsware "Warescription" for Murphy's other books (which gives you access to the latest and greatest versions of them for a year, plus perpetual ownership the last copies you downloaded before the year ran out) and Meier's book (if you really hate ebooks). Personally, I'd recommend the Warescription AND Meier's book :)

(*)1280x720 is the rock-bottom minimum resolution viable for comfortably reading an O'Reilly-Manning-sized book in pdf form two pages at a time. 800x480 is just a hair below the resolution you really need to comfortably read ONE O'Reilly-Manning sized page at a time.