I wouldn't get a parenting guru book i.e Gina Ford, baby whisperer, no cry sleep solution.
I'd buy a book like the baby centre book, tells you what to look out for if they get ill, what sorts of things they do week by week etc. Doesn't tell you what to do, just is a good reference if you have a question.
If you really want one, work out what kind of parent you are first - if you still need a book then you can choose accordingly.
Basically the parenting books go as follows:
Gina Ford - all about strict routine and getting your life back. Not baby led, about parents needs. Not afraid of letting the baby cry to enforce the routine chosen for the baby. Is a hard book to follow if breast feeding.
The baby whisperer - emphasises listening to baby but still emphasises routine. Is a fan of 'pick up put down' which is another sleep training method, but doesn't involve leaving baby. Is still a big fan of routine enforced by parents, but is more baby led than Gina ford. Breast feeding advice not great.
The no cry sleep solution - this is the most baby led of all the ones I've mentioned. Is a book for breast feeding co-sleeping parents, though the advice can be used if you aren't doing this. No routine enforced, all about listening to the baby.
You won't know what parent you are before baby gets here... your baby can dictate what kind of parent you are to a certain extent - some love a Gina ford routine, some need the closeness of co-sleeping. 
Hope that helps 