How are you sewing them? I sew mine with an X across first and then sew them together. Here are some tutorials that might help:
http://ajpadilla.com/tutorials/rag-quilt
http://www.knitandtonic.typepad.com/SimpleRagQuilt.pdf
I used this one for my first raq quilt.
http://quilting.about.com/od/quiltpa.../rag_quilt.htm
This is one I used for a swap. Kids love it!
http://ohsohappytogether.blogspot.co...-tutorial.html