Tammy and I have taken a couple of mosaic classes in the past. It's a surprisingly approachable and fun activity. It's amazing how you can turn pretty mundane things into these amazing looking mosaics. Today we went to Mosaic On A Stick. Mosaic On A Stick just opened about 6 months ago and they sell mosaic supplies and teach classes. Additionally, they have an open workspace where you can just come in and work for however long for a fixed fee. It's a really nice place and the people that run it seem great.
Try it out! You will enjoy it.