Replaced timing belt and need to set the timing marks

The 3.0L is the same over more than ten model years and all the car and minivan models, so you can use any service manual. I can tell you from memory there is a pointer at the 2:00 o'clock position for the crankshaft sprocket, and there's a round dot on the sprocket. Each camshaft sprocket has a 1/8" triangle stamped between two of the holes in the face. The rear sprocket's triangle goes at the 11:30 position and lines up with a notch bent into the stamped steel rear cover. The front sprocket's triangle goes to the 12:30 position and lines up with a corresponding notch on the rear cover.

All the slack in the belt goes on the rear side where it leaves the crank sprocket. That is the side where the tensioner pulley sits. Loosen the bolt, then the spring is supposed to set the belt tension. Tighten the bolt, then rotate the crankshaft two complete revolutions, by hand, in the normal direction. If you go too far, go another two revolutions. Never back up. This puts all the additional slack by the tensioner pulley. Loosen the bolt again, but this time, do not rely on just the spring to set the tension since the pulley arm can stick due to rust, or the spring could have lost its strength. Use a small pry bar to tug on the tensioner to be sure it is putting sufficient tension on the belt, then tighten the bolt. Rotate the crankshaft another two revolutions, then recheck the timing marks.

Watch for signs of engine overheating. If it is running hotter than normal, the timing belt is likely not tight enough and it's slipping over the water pump pulley.