I took the one last year, (Invertebrate Zoology) and even though the reading and lecture list was too much for me to keep up with, I still was able to download the info and finish it at my own pace!
It opened up a whole new world for me with my reef tanks - the world that you can't always see with the naked eye!
I've already signed on for the 1st one. Starts in January.
Mitch 8)