I stumbled across a collection of presentation videos archived at Google Videos that discuss various aspects of photography in detail. The topics vary widely and even include some astrophotography presentations. There is a ton of material here and I have only begun to review it. The material is very detailed and at times overly technical, but hey it is Google. One interesting tidbit I found was a discussion at the end of Ben Lutch's Astrophotography presentation where Google is mapping the entire heavens with images from anyone willing to contribute their astronomical photos to the project. Depending on your interests, there is a wealth of information on this site. I encourage you to check out the topics and see what catches your eye. Here is a link to the search results for "phototech EDU" at Google.