Can anyone point me towards a beginners welding course in the Hampshire area - would need to be evenings.

I have tried the local tec in Basingstoke and they ahve run courses in the past, but nothing currently.

Primarily interested in MIG at the moment, but want to get a good understanding of equipment, principles, practices etc.

Would you not want to just try it?
Thats what I did, bought a cheap £50 welder and practiced on unimportant parts that looked crap and werent strong, to ones that were strong but still looked rubbish and evetually they got neater. Still not perfect but more than adequate!
Check out http://www.mig-welding.co.uk/ for loads of good guides.

Have welder (or access to one) and can weld after a fashion (used to weld at work many years ago), but wanted to get some proper training to progress a little further.

i'm thinking the same. want a proper job, fed up of silly jobs for rubbish money. thinking of training properly as a welder.
seems to be a new tidal power project starting up here soon, will be needing welders by the looks of it.
just got some advice off another member on here, sure he'll make himself known if he can give any more advice, but local colleges will have courses, get on one of them, and they'll point you in the right direction if you want to go any further with it.