That's a great question! Rest assured, that you won't lose anything you did with the trial version.
Once you get the full version, we'd recommend that you uninstall the trial version before doing anything. Simply go to Start > Control Panel and then choose "Add/Remove Programs" and uninstall the trial. That will eliminate any chance of confusion by having two versions on your computer.
Now install the full version of Scrapbook MAX! and start it up. You'll see all of your projects waiting for you, just like you'd expect. To eliminate the "trial" message that was watermarked on your published projects, simply open up a project you made with the trial version and then publish it again. Voila!
Scrapbook MAX! 2.0 is here!. It's simply better digital scrapbooking software!