The following video is the instructional video that came with my looms and it is somewhat helpful.
http://www.youtube.com/watch?v=aeZmkH4DLCI&feature=related
Pictures! They are worth a thousand words, right? I have made a few blankets but for some reason I did not take pictures of all the steps of one blanket so I have to use pictures from different ones :)
This is a square that I made on the large Butterfly Loom.
So far, I have only crocheted around to join each square. The first time (the pink and black blanket) I followed the directions on the Butterfly Loom website. I did three double stitch per loop. 
And when I got the corners I double stitched one, chain three, and then double stitched one. 
This is what the finished square looks like
After crocheting around all of the squares I just whipped stitched them all together, and viola! A lovely blanket!
