It depends on what you are after. If you want to restore your power, then TBH, not much will need doing. If you want a new engine then everything will need renewing. Assuming you want to restore lost power, I will base this list on that.
You will need to remove your head and dismantle it, ie, remove cams, tappets, valves and springs. Make a note of what goes in what position, ie which valves came out of which hole, tappets etc. Give the head a very good clean, removing as much of the carbon as you can get out. Do the same with the valves. I do this by fitting the valves into a pillar drill and turning it on slow speed, whilst applying wet and dry to the valve until it comes up shiny. I then check the freeplay of the valve in the valve guide. You probably won't need to change the guides, but it depends on what your goals are.
The head itself will need a skim. I would resurface it only to flatten the surface and not to increase the C/R. I would then just lap the valves back into their seats. You don't need to go too far with this. A thin abraised line is sufficient of decent sealing.
The engine will need dismantling. I would take the crank to a specialist and have it dimensioned to see if it needs a grind. It probably won't so new shells would suffice. Both big end and main end. Also get him to dimension the bores. Again, they will probably be ok, so only new rings would be required. These would need to be gapped and the pistons would need to be well and truly cleaned without being scratched, including the ring grooves.
The parts new I would replace as they are cheap enough would be the tappets, big and main end shells, piston rings, oil pump, head retaing bolts and of course a full engine gasket set.
I did this on my 8v, and it only cost me a couple of hundred quid, plus time.
If I think of anything else I will put it down later. 5 minutes thought on an engine rebuild is not enough!
