Where do you start on this?, there must be so many!! If you don't have a specific area of interest it can be hard.
I would imagine that some of the older books out there are worthy of notice, and I would be cautious of any jazzy looking mainstream books, given the wow wee 'Lets Do Digital Photography' factor. The techniques stay the same digital or otherwise, and for that reason , a trip down to a decent library will pay dividends, as well as save you a few quid. Alot of the older titles stay in print - because they are so good.