Check out the University of Wisconsin-Extension "Continuing & Online Education" courses at their website -
http://www.uwex.eduI've attended their Writer's Conference in the spring where I've heard from many who have taken their courses - with varied success depending on what they took and how well it fit into their goals. They also offer several workshops during the course of the year in fiction (genre and literary), non-fiction and poetry. I've attended their last two spring Writer's conferences and learned a great deal from the main speakers as well as the break-out workshops. If you attend, you can also sign up to pitch your projects to agents/editors who come for that specific purpose.
Also, if you check out magazines like The Writer and Poet and others, they always have loads of ads for online classes and workshops through various colleges and organizations.
If you enjoy writing in a particular genre, try finding an association for writers of that genre. For example, Romance Writers of America offers its members online workshops and classes aimed specifically at writers in that genre. I know of state and regional writing orgs that do the same.