I am planning to study the impact of guided access to online revision materials on examination performance. Over the next 10 weeks I will be giving one Year 11 class an extra 3 hours access to online revision materials during the timetabled day. I have set up an area of my website to host the resources
http://www.educationforum.co.uk/casestudy.htm

Currently it is all free stuff. There may also be some funding available to purchase subscription based material. I am aware of samlearning.com and the Guardian's Learn as possible resources to purchase, but if anyone knows of anything similar and indeed better covering a range of subjects please post your ideas here

The Guardian's Learn is very good (slightly biased view since I write some of the geography and citizenship lessons :-) but it's not what you'd call a dirt cheap resource, and I feel it is also a little limited in it's revision scope.

I see you link to Internet Geography, a site that has been dormant for 4 years, but is now being reviewed and updated, so the dead links should begin to vanish.

I'd suggest The Geography Site (www.geography-site.co.uk), and the features section of online Geographical (http://www.geographical.co.uk/Features/index.html) as a great source of case studies and background info during the revision period and throughout the year.

It will be interesting to see whether your students find the sites useful, and if not,what was lacking from them.