what are the laws about copyright when selling stuff in my shop?

[danchip]

i have a shop and sell art and pictures and stuff and i've started to buy books and cut out stuff and put it in mounts and sell it from the shop. the stuff is fairly obscure, some quite old, some from the seventies and eighties, newspaper cuttings, old adverts out of magazines, science fiction books, books on cinema lobby cards, photos of old film posters and art etc. i am slightly concerned that there may be a copy right issue, advice of info would be fab, thanks

[mobjob]

its prob different in different places but where i live you can reproduce 6% of the book or one whole chapter of a book (whichever one is greater i think)