I bought mine from Ken Muir last year -now I want more :D If you do buy from him you get a free fruit growing book which is quite good (for the price) -otherwise the 'Fruit Garden Displayed' by Harry Baker, I think, is very good. You've still got time to read it before doing anything this year.
You should plant during winter, you shouldn't get any fruit the next year -because you are supposed to take all the buds off to let the tree establish. After that how soon you get fruit depends on the variety, rootstock, the form you're growing in, whether you've been a good boy/girl all year and how many goats/virgins you sacrificed.
As to varieties -there are a lot of 'apple days' coming up in October (Ken Muir are having one if you fancy a weekend break in Clacton -no? don't blame you ;D), google should find you loads. My tip would be to go along to one of these and try a lot of different apples out, we did this last year, and get varities suited to your situation and what you want to do -we should have done this last year.
I've got the bug and want to grow some more -but my plot doesn't have much depth of soil, about a foot over clay, so if anyone more experienced has made it thus far, can I get away with dwarf bushes/pyramids in this?
Jeremy