check for coolant in your oil ... a blown headgasket will let them mix.

also could be the o-ring on the distributer ... no matter how many times i've replaced mine on the sohc that bish still leaks.

I would suggest you have a friend or mechanic look at it to determine where the oil leak is coming from first.

After determining where it is at then proceed to get a good tech manual or a good internet link on how to replace the headgasket, you wouldn't really need a manual for a valve cover gasket. BUT YOU WILL FOR A HEADGASKET.

It has the proper way to torque down the headbolts after replacing the gasket. You'll want to make sure you don't put digs into the block or the head when you go to remove it. And since you have the head off its all nice to have it milled to have a nice clean seal before putting it back on.

Also becareful not to put the headgasket on upside down, sounds impossible or stupid but it can happen.

After you put it back together you'll need to set the timing and that requires having the engine to TDC.

There is a lot more than this. So I will say if you choose to take it on yourself have someone help you out, walk you thru it or take it to a shop where it can be done.

For the headgasket, if you are running a normal OEM setup spend the $$$ on the OEM headgasket.