Here is what I would do:
- remove spark plugs
- turn the crankshaft until #1 cylinder is at TDC on the compression-stroke

TDC is found when the mark on the distributor gear cover faces 0 on the crankshaft pulley. To make sure that it's TDC on the compression-stroke put your thumb on the spark plug hole of #1 cyl. While turning the crankshaft towards TDC: if you feel air being pressed past your thumb, that's the compression stroke.

- with #1 at TDC, take off the distributor cap and determine the position of the rotor relative to the electrodes in the cap. Its hould be slightly past the electrode of #1 (past, because of the advance). *

You know the firing order, so the next electrode the rotor encounters is the next cylinder in the firing order. This will help you to connect the HT-leads in the right order.

With the valve-cover off you will be able to see which valves are open and closed, and while turning the crankshaft also the ones that are opening and closing. With the valve cover removed, you can also see which are the inlet and outlet valves because they are facing either the inlet or outlet ports of the manifold. Maybe now is also a good time to check and set the valve clearances and replace the valve-cover gasket.

* If you want the rotor face to face with the electrode instead of slightly past, then first turn the crankshaft back slightly so that the mark faces the static advance (you can find the static advance in a manual like Haynes). If static timing is 10 degrees BTDC, then the mark should face 10 on the pulley in the 0-30 degrees part of the timing marks.