Keep it in a cool room and mist the shrub. Come early spring start putting out during the day and into a frost free greenhouse or similar over night. Should be fine planted out about May time.

It should be acclimatised to keep it outside from May as per Moon Growe's advice so you will not need to bring it back inside next winter.

I have several azaleas in the garden that started out as house plants. Some are flowering now. I agree with MG's advice - cool room now then the plant hokey cokey (as someone wrote on the question above) in spring and into the garden some time in May, depending on the weather at the time.

There are two different azaleas sold as houseplants - by far the commonest is Rhododendron simsii (prev. azalea indica, commonly known as the Indian Azalea). This one is a houseplant - needs a cool room, can be stood outside in a shady spot during summer, must be brought back into the house in autumn. The other is Rhododendron obtusum, the Japanese azalea - this one is hardy outside, and once acclimatized, can be planted out. You can tell the difference between them from the size of flowers and leaves - the first has rather leathery leaves with slightly hairy undersides, one and a half inches long, with open, bellshaped flowers 1.5-2 inches across. The second one (japanese, hardy azalea) has glossy leaves 1-1.5 inches long, with funnel shaped flowers about 1 inch across, in other words, smaller leaves, smaller flowers.

Thank you all, its been a great help and I shall do what I can to keep it alive.