Any Apple gurus?

[pops]

My old laptop is more or less on the verge of going belly up and thinking of replacing with an Apple one. However, knowing sod all about comps, I have no idea which.

Called into the shop in town today and saw the MacBook Pro and the MacBook Air. What's the difference? I know I could ask in the shop but they'd sell me the one that suited them to sell.

Don't really wish to pay more than £1200. The only things it'd be used for are internet access, typing monthly invoices and keeping pics on. Not into gaming or watching films on it etc.

What I do like on a comp is speed of doing things e.g. starting up, opening programs,and general usability.

Any ideas which would be the best suited? My current one is 6 yrs old and has been all over the world in a rucksack and has stood the battering well. A new one wouldn't leave the house these days.