Notalone You will be in Charity Shop Heaven at Collegiate Cresent. On Eccelsall Rd (downhill from Collegiate Cres) you have Oxfam, Cancer Research, Help the Aged and Marie Curie. Also a little vintage shop on Sharrow Vale Rd. Although you'll have to resist Fat Face and White Stuff. Actually think Eccy Rd Oxfam might juts be books and fair trade dried foods now.
Anyway, uphill from Collegiate Cresent, in Broomhill, there's a big Oxfam, Shelter (or Scope, forget which, and a couple of others. That Oxfam does furniture too, where I've got a few nice bits.
There is also an Oxfam Books and Music shop on Glossop Rd/West Street, which is pretty good.
In Leeds, if you can be bothered to go all the way to Headingly, the trendy, wealthy students keep the charity shops well supplied, although I have also picked up some good bits and bats from the Oxfam opposite the Corn Exchange.
Anyone in Newcastle? Oxfam in Acorn Rd, Jesmond kept me well clothed and entertained for the 7 years I lived on less than £6K/year.