'Right to buy' information here:
http://www.direct.gov.uk/en/HomeAndCommunity/B uyingAndSellingYourHome/HomeBuyingSchemes/DG_4 001398
Use the link to download the pdf document for more detailed information.
Although flats sell fairly easily in some areas, it's usually far harder to find a buyer for a flat than for a house.
Information about exchanging council housing is here:
http://www.direct.gov.uk/en/HomeAndCommunity/S ocialHousingAndCareHomes/MovingHome/DG_1002597 2
(Subject to meeting the rules, flats are just as eligible for exchange schemes as houses are).
Internet access depends upon the flat having a telephone line or cable access. You'll have no problem with a telephone line, since the flat will almost certainly already have one installed or it will have a box so that one can easily be fitted. A block of flats will only have cable access if a cable company has reached an agreement with the freeholder (in this case, the council) allowing them to install cable TV and phone facilities into the building.
Chris