May you never have to use this. But... Builderau.com has step by step instructions on how to recover your DB using Transaction Logs. Do us all a favor and test this process with another server before you actually have to use it. (Hint: Make sure your DB recovery mode is set to "Full" now, not when you realize that you have to recover.)
Yeah, I know, there's been a bunch of SQL Server links here lately but they are relevant to keeping your GP install happy and productive. I'm not famous enough to make news, like say Britney Spears, so you'll have to settle for me passing news on to you.