You mentioned achieving different looks. For general printing, all the recommendations are great (esp. the Larry Bartlett and Bruce Barnbaum books). If you really want different looks, you should get a copy of Tim Rudman's toning book. It is really quite amazing and back in print. It may be only available from Tim's website, though....I'm not sure.
Gentlemen, thank you.
Form your suggestions I picked up a couple of books I was not familiar with:
"Lootens on Photographic Enlarging and Print Quality" and "Darkroom Printing" by Gene Nocon.
Just a couple of dollars each from Alibris.