How do you knit a knitted edge on a afghan or prayer shaw?

First of all you can use a circular needle and pick up stitches part of the way or all the way around the shawl. The other thing which I just today finished it knitting the cirference of the material and I have all four sides done and now all I have to do is weave the two items together. If you do it this way keep checking the measurements as when I was making the sides it would stretch and I had to pull it down a couple of times to make sure it would fit properly. If it is just a little bit of difference you can fudge it by stretching the add-on or squeeze it to make it fit {sorry cant think of the word terminology right now.} Does this help you or do you need further information and if you do just e-mail me.