Here is what I do and why.

4 partitions
First: Windows
Second: /boot
Thrid: /
Fourth: linux swap

This is all thats needed unless this is to be a server (and you wouldnt be dualing a server now would you). The order may still matter, but used to. Windows at least used to need to be first or close enough to first. Then /boot, since its nice to separate the bootloader stuff and kernel off onto another partition. The other two are self explanitory.