Geology is the sort of subject that that you have always wanted to know more about, but have never had the time to do anything about it. Now is your opportunity, and you can cover online most of the basics before planning your field trips to some of the most scenic parts of the UK - and overseas.
http://www.bgs.ac.uk/magazine/geology/home.html website of the British Geological Survey
http://www.soton.ac.uk/~imw/Geology-Britain.htm introduction to the geology of UK
http://www.scottishgeology.com Scottish geology
http://www.geologyrocks.co.uk/ a source of information for the beginner and the professional
http://www3.open.ac.uk/courses/bin/p12.dll?C01S260 Open University course