Its been years since I builded my last pc and I'm now building a new one. But the thing is there are too many new things that I need to learn about. I bought a new Core 2 Quad q9450 cpu and couldn't decide what mobo I should buy.

Q1:Crossfire or SLI? Which one is better?

Q2:I'm planning to do overclocking+I will either going to do 3 way SLI or crossfire in the future (3-4 months later) but for now I'm planning to use a single graphics card which mobo should I pick?

Q3:Which graphics card should I use for now?

Q4:DDR2 or DDR3? Which one is better?

I would be grateful if you can suggest a motherboard that would fulfill all the requirements specified above. If nobody will help I will go crazy soon

Well since you already have the Q9450 I would suggest a P45 based board and go with crossfire. The Q9850 struggles to get high FSBs and the P45 boards help. I liked t he ASUS flavors and have used the P5Q Pro. The 4870x2 will soon be released and if you really need the graphics power you could crossfire two of those but I think the with P45 boards x8 PCI-e in crossfire mode would hurt performance so x38 and X48 boards may be a better choice if you are emphasizing graphics. I would go with DDR2 PC8500 in 2x2gb sticks for 32 bit and 4 sticks with 64 so choose a board that doesn't used DDR3.

It all depends on what resolutions you want. If you plan on getting a 30" monitor that will need a far stronger rig than a 22".

There is no difference in performance between DDR2 and DDR3. You could argue that buying DDR3 now would be good because the next system might still be able to use it... but it's expensive and the boards that use it are mostly more expensive.

So, it makes no sense to use DDR3.