I don't think I've seen any proper discussion of the composition of UK public spending amongst the current debates on cuts and benefits, so here are a few charts from the IFS.
From a 2009 survey of public spending you can see what the main categories are - social security, NHS, education, and defence.
Then this observation compares mid-Labour pre-crisis spending in 2003 to estimated spending by the end of the current government in 2007. They aren't all that different, except for increases in health spending, pensions, and debt interest.
Finally this 2012 survey of the benefit system breaks down the largest category, social security, into recipients. Unemployment benefits make up just 2.6% (though people out of work will also claim some of the low-income benefits such as housing allowance, and there are no doubt some people on sick and disability who could manage some form of useful paid activity, even if the reforms to the testing regime have been poorly handled and very unfair on some people). Nevertheless, 60% of social security is for the elderly and for children.