I second or third on the Borneman book, very good. Not as much pictures but much more practical information is 'Coral Propogation, Reef Gardening for Aquarists' byt Anthony Calfo. I got it off Amazon a few weeks back and it is excellent. It's mostly text with some diagrams and pictures but the information is priceless. Also if you like taxonomy like me the 3 volume Baensch Marine Atlas is good. You can get them softcover online for about 30 each.

I've leafed through the Sprung/Delbeek books, looks like a lot of good info just dont want to spend $60 each right now.