Originally Posted by 4P_Bulldozer
1. Fan holes that you do not use should be blocked so the air flows through the Case as it was designed (too cool the Components) and not in the front and out the sides. You will need to run all the Fans (noisy?).
2. What does the other side look like.
3. Does it actually fit your current Motherboard and any you might upgrade to.
4. Often, two rear Fans are enough.
You can probably Google (Images) for Photos of that Case from all sides and maybe even one with your Motherboard in it so you will know exactly what it will look like.
There's no real need to block the holes unless you are trying to run some kind of wind tunnel setup. I can see how some would think it but it really doesn't make much of a difference either way.
If you only have two fans you should put one in the front pulling air in, and the other in the back to push air out. If you have an uneven number of fans (or an even number but some are larger) then have the odd/bigger fans pulling air in. Also, exhaust fans should be in the back and/or top of the case to promote proper air travel direction and to actually get the hotter air out of the case.
Extreme112, look for a case that puts the side fan either over your graphics card or just off-center (front or below) of the cpu. those are your hottest components and will need all the cooler air you can get to them. I say off-center (front or below) so as to not only bring in cooler air but to help push the hotter air away from the CPU cooler.
My fan setup is two in the front and one in the side over my GPU pulling in air, and two in the top and one in the back as exhaust.