You have to separate USD$, BTC, and the books in your mind.
Turning USD into BTC and back to USD is something that happens either in person (like localbitcoins) or on an exchange (Like
www.mtgox.com).
As far as the book is concerned, USD doesn't exist. If you want to deposit 1 BTC into a book, the book will give you a "receiving address" to send the BTC to. Once you send the BTC, its usually credited within minutes. When you want to withdraw BTC from the book, you will enter YOUR receiving address from your wallet into the books website, and they will send you your balance within minutes (usually, some books delay a few hours).
In short, how long does it take to get BTC in and out of a book? Almost instant (minutes).
Now, once you have the BTC from the book, you can either keep it as BTC, or turn it into USD at an exchange. Once you are all set up with the exchanges, it literally goes like this:
Green Text is USD, Blue Text is BTC:
Bank account to Dwolla (2days), Dwolla to Gox (1day), GoxUSD to
GoxBTC(instant), GoxBTC to your wallet(instant), wallet BTC to the book(instant), book BTC to your wallet (instant),wallet BTC to Gox (almost instant), GoxBTC to
USD (instant), Gox to Dwolla (1day), Dwolla to bank account (2days) Again, I highly recommend you read through post #13 on the gambling links thread and the screenshots i sent you.