So far, so good! At this point just make sure that each layer is secured (either individual layers or all 3 together) to some flat surface. I use my cutting/craft table and larger binder clips. Next step is to baste all 3 layers together. You can use either safety pins or thread. Start in the middle of your project and smooth as you go. With either method, I usually put my pins/thread about a hand-width apart in each direction. I only hand quilt so I don't know what method will work better for you if you are machine quilting. And depending on your quilting pattern, it may be better to mark your complete design before quilting. I usually mark as I go but that works best for hand quilting as far as I know.
Holler if you need more help/info. And good luck. Sounds like you're doing fine so far.