Welcome aboard! I read your comment on the other thread about backing over your sewing machine. I think you can call yourself a quilter already. I got a good laugh out of that.
As far as not knowing where to start- have you discovered quilting blogs yet? One of the best IMO is crazy mom quilts.
http://crazymomquilts.blogspot.com/
She has some very clearly written tutorials. Also, Moda Bake Shop has a lot of tutorials for their precut fabrics.
http://www.modabakeshop.com/
I design my quilts like you are- with graph paper and colored pencils. My kids know NOT to touch mom's colored pencils! LOL!
I think you already have enough sewing skills to do this! If you just jump in and post topics on here when you get stuck I am very confident that you will get awesome answers and encouragement.
Also, you can check quilting books out from the library! Happy day when I figured that out!