This post from the Coope Boyes & Simpson workshop thread is valid here so I'm copying it:

Our workshops are mixed ability, but not really suitable for absolute beginners (e.g. someone who needs to learn how to find middle C on their instrument). On the other hand, anyone who can already do everything that a workshop is offering doesn't need to be there.

We try to make our workshops inspirational as well as instructive; I hope that doesn't sound pretentious. We hope that people will take away a few solid tunes, songs or techniques for future use, and also that they'll get some ideas to work on and develop in the longer term. We ask our tutors to make sure that the participants do plenty of playing and singing rather than sitting still being lectured.

Unfortunately we aren't in a position to offer full courses: for that you need Folkworks, Hands-On Music, the Wren Trust, and all the other excellent people working steadily away to help people perform traditional British music.

While I'm at it, you'll finding reasonably-priced Lewes area bed & breakfast accommodation here; in the summer months, there are camping and camper van facilities at Spring Barn Farm Park on the outskirts of Lewes.