Hi Christine,
Amy definitely has videos for this!!!

Well, she has videos for a knitside bar increase anyway.

But once you see the video, you'll get the explanantion for the purlside.
The video for the knit bar increase is on this page:
http://www.knittinghelp.com/knitting...ons_explained/
see: k1 f&b aka kfb
On the purlside of your work, you would do "purl the front of a stitch, then purl the back of the same stitch" (see Amy's abbreviations page).