I've been on the prowl this week for online classes geared toward mixed media art offered for free. I was prompted to do so based on the distance learning courses I've been taking through UMUC. I've been enrolled since December of 2006, working toward a BA in English, and the act of learning daily has been very gratifying. That being said, here's what I've found for your learning pleasure:
Free Class: Altered Tin Class by Jen Kinton-Bailey: I started creating altered tins (some refer to them as shrines depending on the method and meaning of creation) when I was an active member at nervousness.org in 2003. I would have loved to have a link like this, rather than going through the trial and error (and frustration) process!
Access Art: Workshops: I'm still in the beginning phases of exploration here and I've discovered, so far, that this isn't specifically geared toward mixed media arts. However, the foundations of learning offered here are essential and able to be incorporated into mixed media arts.
I hope you find these links interesting and useful. I would love to read about your experiences or see examples of your accomplishments in the comments section. In the meantime, happy learning!