You should now install the memory Dimms (Dual in line modules) These are fitted to the long memory slots next to the processor. Open the two white levers at each side of the slot, and press the DIMM into place, noting that it can only be inserted one way. The plastic levers close automatically.
It is worth noting that some motherboard only allow memory to be used in certain combinations, and in certain sizes, consult your motherboard manual.

The motherboard can now be fitted to the case. You will see that there are a number of holes in the case, some of which will corespond to holes in the motherboard.
Insert a "stand off" into each of these holes and tighten the screw.

The motherboard is usually made up of several layers of insulator with fine conductive strips in between. Any stress applies to the board will result in it breaking, and they are impossible to repair.

This particular brand of motherboard doesnt have any holes on one side, and small rubber standoffs must be used on that side. These provides plenty of support when the drive ribbon cables are installed.

Place the motherboard in the case, ensuring that the board sits snugly and all of the standoffs mate up with holes in the board. Your motherboard will have been supplied with several different types of screw, and it important that you use the correct type and size of screw. Do not overtighten the screws.

Consult the manual that came with your motherboard, and decide which of the case leads you need to connect. As a general guide, there should be
a) case speaker
b) case switch
c) reset switch
d) hard disk activity light
Each lead should be plugged into the correct socket, and you should make sure that the polarity of the lead is observed (+ve goes to +ve, -ve to -ve)