What size do you need. Usual background rolls are 2.72m wide by 11m long for studio use. I use to use white, black, green and blue (the last two are easier for keying/masking) as the studio was used for video also. These are quite big for home use, then you need something to support them.
I used to use the Colourama rolls
Do you want backgrounds with images on? like these:
http://www.creativitybackgrounds.co.uk/
Plenty to google.
For home use, some good thick dark material works well, as does good bright white cotton sheets of a good quality. Make sure they are ironed as it's amazing how the creases can show sometimes and it saves fixing in post.
I've used a £6 simple shower curtain before, hung over a curtain pole to patio doors. I didn't need to use extra light as it was a bright day, but tape on the doors in the right place made it look like a window.
For smaller things, like dogs etc, I've got away with 1m paper rolls from Range. Very cheap, they have a multitude of colours and the black is very black, the white is bright white but you've tight framing (or sort in post)