Congratulations. I'm sure you'll be happy with it
One of the ladies in my guild has a 15" Bailey. I used to have a 15 but now I'm a Lizzie sit down person.
The best advice I got for frame quilting was to load cheap sheets with batting of course and then to start quilting song lyrics, poems, etc all the way to the bottom. You'll get the movements down with the alphabet and won't get as bored practicing if you are able to sing along more or less... and by the time you get to the bottom of the sheet, your stitches will look nice and pretty - probably sooner than that... then start again. I have also heard to do as another suggested - quilt in one color thread all the way to the bottom then load again and do it over and over until you are happy with your stitches.
Oh - a few of the big machine quilters in my guild are in love with Glide thread. It's inexpensive, doesn't lint up and has a very nice sheen to it. You might want to give it a try so you have thread ready to go.
Also if you haven't already, join the Bailey yahoogroup. They are absolutely fabulous
Best of luck