I just signed up to be a boxer.  I have a 1 book deal arranged already.  How long do I have to get it in the mail? I'll probably mail it tomorrow since I have other books to mail.  But I can't find anywhere where it says I have to mail by a certain day or where to mark it mailed. Do I just PM the person?

For BOBs, there is no time limit to complete a transaction. There is a place to mark it as mailed, have you printed the label yet? Its been a while since I did a BoB transaction, but I think with each step a new box pops up with the next step to be taken.

Once both parties have pressed the "accept" button, then the option to print labels comes up.

As soon as you have pressed the "print label" button, the button to indicate you have mailed it comes up.

The trade won't time out automatically, but I understand that R&R consider anything over 30 days to be worrisome.

I'd recommend trying to follow the same 1-week timeframe for regular trades.