I have read all those mainstream pop books like what to expect, up the duff, and baby love. I did enjoy reading them to a certain extent but i also found a lot of the information on what you should/shouldn't do a bit daunting... especially the parts about labour. Much better options IMO...

Gentle birth, gentle mothering by Sarah J Buckley (Aussie)

Our babies, ourselves, by Meredith Small (USA)

Parenting for a Peaceful World, by Robin Grille (Aussie)

and just about any book you can buy from mothersdirect.com - they have a pregnancy and labour section.

ETA: what i liked about these kind of books is that they are backed up by research and they are written a bit more 'intelligently' than some of the others!