Ayup Nick - there's plenty of folking within easy striking distance of Leeds - Otley (Wed), Pool-in Wharfedale (Thurs), Bradford (Thurs)
All these have singers/musicians nights at least once a fortnight - there's the Cardigan Arms, Leeds fortnightly meet too. All details to be had from Tykes News (as the Duck points out). It can be bought at shops such as 'Jumbo' or 'Hobgoblin' in the city - but the web address the Duck gave is a grand starting place.
There's a goodly amount of folk 'concerts' in Leeds too - venues such as the Irish Centre, New Roscoe & City Varieties all put folk artists on from time to time. Oysterband have just been - though there's a good folk/rock night to be had at the New Roscoe on Wed 18th Dec - two bands - 'Slide' and the 'Duncan McFarlane Band' for only £4!!!
Filofolk's yer answer - run by Jim Lawton - give him a ring - he'll tell you everything - he's an ace cat (sorry Duck!) - Byee - HFA