I'd highly recommend DigiGuide - an electronic guide you install on your PC/laptop:
- excellent search functions
- listings are weeks in advance (e.g. SkyArts is currently listed up to 30th April)
- various ways of viewing the listings
- quick
- can set up favourite programmes to build a daily "My TV"
- includes all the channels you could imagine
- very clear and understandable
- good customer support
Price is about £10 per year - negligible compared to Radio Times, etc. & far more useful. In particular, it's great to be able to get detail about programmes on radio or some of the more obscure TV channels that are often overlooked by the magazines.
http://www.digiguide.co.uk/