I was most interested in the 'Digital' class to improve my skills and make better use of Photoshop.

-I would try going out and taking pictures, post them on a forum or website like alt.binaries.photos.original and seek comments. It you need work on composition, etc.you could check a book out of the library or a free on-line course such as http://www.photoworkshop.com/ or follow the advice in http://194.100.88.243/petteri/pont/Pontification/ba_Don't_Be_A_Bozo/a... which is specifically geared to 300D owners, but applies to all.

While I admit to having no experience with an on-line course, I can only guess that it is a more formally set up and more costly outline of the foregoing.

-Seems sort of expensive....and just how interactive will it be? Check with your Community College to see what they offer.