I know I've gone over this before - but it's been a while, so here's a freebie:
Materials:
1 Valve Cover Gasket (I prefer cork - in use, it will swell with oil and help seal.)
1 set SBC Valve Cover studs (cast length for cast covers, stamped length for stamped covers.)
1 tube LocTite #518 Gasket Eliminator
1 torque wrench (for reassembly.)
1 7/16" or 11m/m "flex" socket (shorty socket with inbuilt universal joint.)
Instructions:
Disassemble, clean, and inspect. Note any minor flaws (small gouges and the like,) and correct any major flaws (fill and grind, usually.) Don't change your oil yet - you're going to be dropping stuff into it, and you want to get rid of it.
After cleaning, flush all particles down thoroughly with carburettor cleaner.
Insert studs in four holes about the perimeter - I don't put them right in the ends, but I'll do something like second hole from each end. Make sure both of the mating surfaces are free of the solvent you used to flush particles down with.
Coat both sides of the gasket with LocTite #518.
Lay gasket in place.
Lay valve cover in place, overtop gasket, using studs to locate.
Install nuts finger tight.
Go have lunch. Or read the paper. Just do something else for about a half-hour.
Come back, put the socket and extension on your torque wrench, and set to spec (I believe it's 84 pound-inches/7 pound-feet, but you can verify on my site. Specs there are taken from FSMs.)
Install all remaining screws finger tight. Once all screws are in place, torque in "criss-cross" pattern to spec, working gently.
Change oil and filter. This will get more crud out of the engine assembly than draining it before you start. I make oil changes the last step of any job that requires "breaking the oil seal," save anything that involves removing the oil sump directly.
NB: I consider a torque wrench mandatory for this job - whether you're using a rubber gasket or a cork gasket. Either way, it's entirely too easy to crush the gasket beyond utility, and you'll be tearing it down and starting over rather shortly...
NB: If you forget and drain the oil first, do not put the plug back in. Make sure it's out, and flush the particles straight down the sump and into a drain pan. You'll get more out that way.
After doing the job, change the oil filter (and top up the engine oil) after about one week of operation - just to finish getting the crud out that you loosened up.
NB: While you've got the valve cover off, clean the CCV ports and baffles - you're there anyhow. Carburettor cleaner and pipe cleaners will usually do this job quite well. (You don't have pipe cleaners in your toolbox? Why not?)