Fans are there to aid cooling, yes.
So for example, an adequate cooling solution would be for fans to be dragging cold air in from outside the case (usually at the front), and then for fans to be expelling hot air from the case (usually at the back). This would aid cooling inside, and should mean that the inside of the case is only slightly warmer than the outside air temperature.
Computers are basically plug and play, meaning that all of the components slot together in some way that once fathomed is easy.
The hardest part you'll find to install is the CPU/heat sink as the fitting can be quite tight, but don't be scared to give it a bit of force to latch it on. Just of course, not too much.
The motherboard, which is capable of holding CPU's with a LGA1156 fitting means that any CPU in the i7 branding will be supported. If they carried on with that socket for future CPU's (they do change a lot) then chances are a BIOS upgrade could mean you could insert an even faster processor in there later, if one existed.
Trust me though; if you look after your computer, you'll be happy with them for a very long time. My build now is about 4 years old, and its still relatively within the times, and isn't considered old at all in my eyes, and other than a GPU upgrade and a RAM upgrade, will be happy with it for quite a few more years to come
I doubt I'll ever upgrade the processor on this rig while it lasts.
On another note, if you are to be gaming, I do suggest you buy at least a cheap sound card from the likes of Creative. It'd beat the hell out of the offering built into the motherboard, and usually come as a PCI card, or newer ones as a PCI-E 1x card. Both which are supported on that motherboard.
Sound quality for one will be most improved. Second of all, even though its a quad core, it puts less load on the CPU. Trust me, its worth it.