Gladly
and your questions are not stupid !
1. The board has two PCI-e x16 slots, yes with Crossfire support which is for ATi cards. Therfore you can theorectically gain upto 1.6x of GPU performance by using two identical cards connected with a crossfire cable ( you mainly have to use identical cards in crossfire). The two cards behave as a single GPU and therefore your performance gets a major boost.
Therefore you need to buy the graphics cards which can be configured/supports in crossfire. More about crossfire. (click here)
Also you will need a 750W rated PSU (from Corsair, Coolermaster or Antec) if you are going to use two graphics card in Crossfire on this board.
Although this board doesnt run in CF 8x8 mode, rather in 16x4 mode which isnt that good
2. The Q9450 will be better than the AMD Athlon II X4 however it costs like double of what this processor costs. A Phenom X4 will however beat this Quad core at a lower price.
It doesnt make sense to buy the C 2 D or C 2 Q series now, especially since Core i5 is much better if you're going to spend 11k on just the processor. Only gripe is that the motherboards for Core i5 are really expensive right now