The best place for academic jobs (including quite a few part-time teaching posts that tend to come up at this time of year) is www.jobs.ac.uk . The 'disciplines' they use are not very helpful - and its often well worth looking at 'related' subjects that may have teaching more suited to your skills.
Alternatively, its always worth sending your CV off to the Head of School/dept at other local Universities you'd be willing to travel to - especially ex-polys who may not have the critical mass of PhD students found at Russell group etc. Saying that, they are unlikely to take you on until you already have a bit of teaching experience behind you (depending on your subject)