Depends where you live, and what type of jewellery you make!
Best thing is to look at local colleges, sometimes the less 'mainstream' ones will do courses in jewellery making.
I'm not sure that working in a bead shop would really get you very far, the one in the city centre seems pretty limited (they do make some stuff, but nothing really complex).
I work full time, and make my own jewellery. When I have time I make pieces to sell, I've sold a few on eBay, I wait till they've got a 5p listing day since you save 10p an item.