Welfare benefits
The Citizen’s Advice Bureau has an online advice guide at http://www.adviceguide.org.uk/
The best place to start to look for Government websites on benefits is DirectGov which has a series of links: http://www.direct.gov.uk/en/MoneyTaxAndBenefits/BenefitsTaxCreditsAndOtherSupport/index.htm
There is an online benefits calculator at http://www.entitledto.co.uk/Default.aspx?AspxAutoDetectCookieSupport=1