Install Cpu fan (CM V8) before or after Mobo install?

I'm Building a new system (never done before) and have a question. Is it best to install the Cooler Master V8 onto the cpu and Mobo before or after putting the Mobo in the case? This Cooler looks big and I'm wondering if it's installed first whether there will be problems connecting other stuff to Mobo due to limited space in case.

Also I'm gonna be using artic silver 5 and have never done before. Any tips?

Build:

Antec 1200
i7 920
Evga x58
Evga gtx260 superclock
6GB Corsair Dominator
1 DVD burner
1 300GB WD rapter
2 WD 500gb (raid 1)
Thermaltake 750w w0116ru sli ready PSU

Regardless what the Intel instructions with the stock cooler say, always install the HSF (and memory) before installing the motherboard in the case. Inspecting the back of the board is the only way to be certain that the HSF is installed properly.

Many aftermarket HFS's require access to the back of the motherboard to instal a backing plate.