Once you've got your quilt top layered with your batting and your backing fabric, and it's taped down so it's not going to move, you're ready to start thread basting. Thread basting would be the best if you were planning on hand quilting your quilt. For thread basting, I use a very long needle, it's called a darner, and a pretty long piece of thread. Obviously for your this size you wouldn't need much, but I usually work on much bigger quilts.
I would start in the center and take a really big stitch, about an inch and a half, something like that. Pull the thread through, and you don't even have to knot it. Just leave it and continue working your way up to the top. Big stitches are fine, because don't forget this is basting and it's all going to come out in the end.
After we did this side, I would go and do ninety degree, and just keep going. You're going to want to put stitches about every four to five inches, and that should really hold it for a very long time. I've had quilts basted for years. Sometimes it takes a while to quilt a quilt.
When you're done, you can just leave the edges. After you finish basting the entire quilt, I usually fold my edges over and put in few big stitches. It helps keep the edges of the quilt from fraying, and it keeps them clean. You just go around until the whole thing is done. This way, if your hand quilting project takes a year or two, it won't matter all. It will stay together perfectly. After you get it done, you're ready to start hand quilting.