Where can I find information relating to radar imagery?

The UK Met Office have an information sheet on the use of radar in meteorology: http://www.metoffice.gov.uk/corporate/library/factsheets/factsheet15.pdf
(You will need a PDF reader for this).

For the images themselves, start by going to:
There are also useful notes attached on the use and configuration of the network.

for the BBC Weather Centre site:
http://www.bbc.co.uk/weather/ and follow the appropriate links labelled 'UK Weather' & 'rain'. However, it is unclear whether this imagery is now (from 2005) 'pure' radar output, or some amalgam of model and radar - not as useful as it used to be.

For 15-minute imagery, with good navigation, speed control etc., MeteoGroup provide the following:
Note that you can also select other areas in Europe to display - truly a major advance in availability since this FAQ sheet was started back in 1997!

and for imagery over Belgium, the Netherlands, NW Germany and NE France (includes East Anglia & SE England on some views), go to: http://www.meteo.be/meteo/view/en/123361-Radar.html or http://weerkamer.nl/weer/radar/ or http://www.buienradar.nl/

and for other links to European radar imagery, try the 'Top Karten' site:

and follow the links via "Sat & Radar".

(NB: there are now commercial sites offering higher spatial and temporal resolution data, but for a fee, e.g. the Met Office, MeteoGroup, AvBrief etc.)