Deanna, first of all congrats on the twins! I have twin nephews that will be 2 in about a month! I hope all goes well for you in your pregnancy.
It's great that you want to start quilting, I get so excited when I know of someone who is just starting out, I have to be careful not to overwhelm them! :lol:
The great news is that crib quilts and wall hangings are such great ways to break into quilting because of thier size and manageability. It will give you alittle bit of experience in all of the phases of quilting before you tackle anything large.
I would suggest you start by checking out patterns on the net (let us know if you need some web-sites) and start getting a look at all you have to choose from, also keep in mind what colors you might be wanting to use. If you know what the twins bedroom colors are going to be it might even help you in picking out which crib quilt to make. Since you will be making 2 of them I would stay simple, which is sweet and precious in a baby's room anyway.
Another thing to look at while your searching for your quilt pattern is the difference between piecing a quilt and doing applique. There are tons of cute quilt ideas doing applique. I personally haven't mastered hand applique but I do alot of machine applique, I think it's fun and I like the way it looks. Either way you will probably be doing some piecing and for a first quilt I would suggest a large block pattern which also would fit into the crib quilt look very well.
Best of luck to you, please get on the board for any other questions you have or come across as you begin your quilting journey, hope I didn't babble too much!