Making reservations through Disney Website?

[ahake]

Well, we decided to wait until my youngest is a little more mature to handle Disney, so we are going next December (2005) I want to book through Disney's website so I have the option to pay it off monthly. My first question is, is this the only site that allows you to pay monthly? Next question is, since we have 3 children we cannot stay at a value resort, what moderate is more bang for the buck? And my last question is, if I book now at the rate they are giving me, and way the rate will change up or down?
Thanks for the help!!