cheapest broadband and mobile providers in UK?

Hello,
I just moved to London from France for 10 months and would like to get
the cheapest possible broadband and to buy a contract mobile.
However, have no idea about what are the best companies here?
My friend recommended some cheap UK internet shopping links
from here but she is not native herself so I don't know if these shops
are cheap or not - so would like to ask your for your suggestions.
Thank you very much in advance!

>> the cheapest possible broadband and to buy a contract mobile.

I do not know about mobiles, but for Bradband start here (ordered by cost)
http://www.adslguide.org.uk/isps/sum...?order=tco512k

and for reviews check here...
http://www.ispreview.co.uk/review/ce...=browse&catego
ry_id=1&x=10&y=11&sortby=avgscore

--
Ian