Ok, so here’s a couple of videos on how to create a pattern using a hand drawn image as well as in Illustrator.  I’ll also add to this with images of a simple grid with a repeated design.  The first video is a little pushy about where she got the idea & going there but the resource is good, quick & to the point.

A little longer, but a great resource as well (digital pattern making)

Screencasts on converting images laser ready files in Illustrator (just in case you wanted to check it out)

Creating a basic grid in Illustrator:

Creating a pattern with text:

Converting a hand drawn image to a laser ready image in Illustrator: