Hi Ian and welcome to the Dis.
Two weeks in WDW sounds like a long time but there is so much to do the time gets used up easily. You really need to do some research before you go and prioritise which parks you really want to do and which you are not so bothered about. If you try to see absolutely everthing you will kill yourselves.
There is an amazing amount of information on these boards to help you. In the two weeks you should easily be able to do all the Disney theme parks as well as Universal and Seaworld. Other options are Kennedy Space Center and Busch Gardens - if you have time.
With regard to tickets. These can be bought online from various sites or from your
travel agent. There are no massive discounts to be had, unfortunately, but it is a good idea to buy before you go so you avoid queueing when you get to the parks. Which tickets you buy depends on what parks you want to spend your time in. There are multi-day tickets for both Disney and Universal/Seaworld.
The site I use for tickets is
www.ticketmania.com. I'm sure other people will have a few more suggestions for you.
Feel free to ask questions on the boards. These guys know pretty much everything there is to know between them!!
When are you going next year?