It might seem a bit early to be thinking about Autumn and Winter courses, but it's well worth looking into now, to make sure you get onto the course you want. Most of the collages, from Universities to VEC's (Vocational Educational Collages) run a range of classes starting from September. These include knitting, crochet, dressmaking, patchwork, etc
The best way to find out is to just contact your nearest college, and get their prospectus. If they are not running a class you are interested in taking, why not ask to see if they would run it. They keep a database of teachers, and if the numbers are there, they will organise a class.
www.nightclasses.ie is a good website for doing a general search to see what kind of classes are on.