I love the colors you chose. Very nice quilt top. If you are nervous about quilting it, take it over to the local quilt shop with you. The ladies over there will have tons of ideas and give you some good advice on designs.
Like the girls said, stitch in the ditch is a very good option for this quilt. You will be surprised how much confidence you will gain just in a short while playing aroung with another sample cloth first.
I started out playing around with a pot holders to see what I could do. Then graduate to a table runner size and so on. You will find that it is fun! Just a different process than the piecing.
You could check out a book from the library on machine quilting designs and learn that way too. Just don't get intimidated. HAVE FUN! That is what it is all about. Some people find that they love the quilting better than the piecing. REALLY!