You will need an accurate torque wrench, Craftsman's, Snap-On's, etc.. "The Good One" they cost a bit over a hundred dollars. Buy the Chilton's Manual, probably 40 bucks, you will need the tourque specs and tighnening sequence if you do. Also a steel straight edge and some feeler gauges to check for any warp of the heads and block. Get a complete gasket set for what you are doing, replace every one that you come across, probably the only cheap things you will encounter. New thermostat too.
If you found the problem before the thing overheated you MAY be fine, BUT!!, you will need to do these checks, if they are out, and you don't resolve them, by "re-decking" the head and/ or the block, the problem will rear it's ugly head when you are out in the middle of no-where and you will warp something.
If you are not understanding any of this and you are not mechanically inclined don't even think of doing it, mechanics will charge you more to clean up the mess you create.