I'm going to assume that you didn't mark the distributor location before removal, or you have rotated the engine after removal.
It's easiest done with a manual transmission. Place the car in 4th gear on a level surface with 5-6 feet clearance in front. While peering down at the crankshaft pulley, rock the car forward just a few inches at a time until you see the timing mark come around. It will come up from the alternator side of the pulley. If you go past the timing mark, don't back up, but continue for another revolution. I find that a small LED flashlight works best for illumination and is small enough to get down near the pulley. You can remove plugs 1,3, and 5 to make it easier and place your thumb or finger OVER, not in the #1 plug hold to feel for compression as the mark nears TDC.
Once you've got the timing marks aligned, mark them with a dab of white paint or white-out correction fluid. Now, take the transmission out of gear, set the parking brake or block the wheels so the engine doesn't rotate.
Since the engine fires on the timing mark as cylinders 1 and 4 reach TDC, you could be 180 degrees out of timing, if you didn't use the compression method. That can be easily remedied.
With the rotor button installed, hold the body of the distributor in the position you want it to sit in the engine, paying attention to the probability that you will need clearance to remove that ignition module at some point, so be sure you have clearance around heat shields and throttle body heater tubes. Having the module at about the 8-9 o'clock position works well.
Point the tip of the rotor button at the 4 o'clock position and slide the distributor down into the engine. The rotor button will rotate clockwise a bit as the distributor gear engages the cam. You may also need to wiggle the rotor button a bit to get it to engage the oil pump drive. If the rotor isn't where you want it, lift the distributor and reposition until you obtain the position desired.
Once the distributor has been seated and positioned as you want it, and the rotor button tip is still in the 4 o'clock area, align the reluctor wheel with the stator fingers and snug down the distributor hold down. With a marker, mark the #1 position on the reluctor and stator. Offer the distributor cap to the distributor and note which wire terminal is at the 4 o'clock position. This will be # 1. Now install the other wires in clockwise rotation, in numerical order.
If it doesn't start or backfires, remove the cap, align the two marks you made with the marker with the method originally described, then lift the distributor and rotate the shaft 180 degrees. Try to start again.
Serpentine Belt:
I find that loosening the alternator adjuster bolt and it's swivel bolt works well. From the top, get the belt onto all the pullies except the water pump. Now, pull up on the belt with both hands, keeping it snug on the other pullies and slide it onto the pump. At this point, I need a second person to insert a prybar against the alternator while I go underneath to tighten the adjuster and pivot bolts.
Start the car and warm it up. Shut it down, insert a jumper in the ALDL and finalize timing with a light, using the method described on the emissions decal on the engine lid. You probably won't be able to get your light into the perfect position over the mark, but you can get it close enough.