I did a night course at a local college for a term. I found the tutor to be very good mainly because she was very open minded to style and content.
However nearly all the other students were older ladies who all hoped to write romantic novels, so i never really had anyone to bounce ideas around.
I think it cost £40, and i would say definitely worth it.
Also entering competitions is a good way to hone your skills, as it makes you edit you work to fit a word count and really encourages you to write worthwhile content that an audience would appreciate.
I found the best competitions were the ones with a specific brief rather than open (write whatever you like). I once came third in a competition where the brief was ‘communication’. It really made me think about how to approach a theme, and i really enjoyed the writing process as a result.
There are forums for wannabe writers, but i found them to be inhabited by quite self indulgent people only really concerned with having their work read rather than critiqing others – That was a few years ago mind so it may be different nowadays.