Always happy to help when I can Connemara. A few other tips...
1) Remember that bitcoin price changes like stock prices do. If you receive a payment today and wait until tomorrow to withdraw, the amount in your account will likely change.. could go up, could go down, depends on what BTC is currently sitting at. In fact, the price changes so often it will probably fluctuate a tiny bit the first 20-30 minutes it's in your Coinbase account. Usually won't fluctuate very much in a day or so, but it likely won't be the exact same as it was the day before if you wait.
2) If you plan to deposit funds into your Coinbase account so that you can deposit them into the books, make sure and use the Card option instead of a Transfer. Card deposits will be available to "trade" (AKA send to the books) instantly. Transfers (as you might expect) will take a few days to process and then become available for sending. If you're receiving funds from another book (like the instance above) then they will already be in your account and you can simply deposit from those and not have to worry about this.
3) Depositing to a book is similar to withdrawing. Choose the bitcoin option at your book and they will give you an address (it will be long and contain numbers/letters just like the one you withdraw using)..Go back to that same bitcoin page in Coinbase and choose the "Send" option instead of "Receive". Enter the address they gave you and the amount. Keep in mind, they will charge a small fee to send BTC (still cheaper than most books charge if you deposit with a card). So, if you have $100 in your Coinbase account you won't be able to send $100, it'll tell you that you don't have the funds until you get below the amount + fees..so it would end up being like $97 or something like that.
Hope this helps anyone trying to deposit/withdraw using bitcoin. If anyone has any other questions you can always shoot me a message and I'll be happy to help.