if your a single parent you will get income support (if not working) think its about £60 per week
everyone gets £20 per week child benefit..
and child tax credits depends on income... there is a calculator on the hmrc website tht will help you find out..
working tax credits you will only get if you work 16 hours or more a week and earn under 18k (i think)
if you are on a higher rate of child tax credits you will also get an exemption card for nhs perscriptions, opticians, dentist etc
if you go back to work you can also claim costs for childcare provided your child is in a registered nusery/with a registered childminder
hope this helps