Ignore the timing mark "dimples" on the rear timing cover; they are always a tooth off. Unless you have some low quality belt, it should have three lines and an arrow on the belt. The arrow should point towards the front of the vehicle and will sit on the span between the two cam sprockets. The other lines should line-up with their respective timing marks on their respective cam or crank sprocket. If it has one dashed line and two solid lines, the dashed line will line up with the mark on the right bank (or, passenger side) camshaft sprocket. If the sprocket turns a little....or "jumps" which they sometimes do because of the valvetrain tension on the cam...it can be easily turned back into position.
Normally, when I do timing belts on these engines, I get a Gates timing belt component kit with water pump (comes with instructions, belt, water pump and tensioner) from Rockauto, Bando brand drive belts from Rockauto, front camshaft and front crankshaft seals/thermostat/coolant bypass hose from Nissan. Some people also like to get a new tensioner spring, which is optional. If the radiator hoses are in poor shape, I'll get new, Good Year hoses from Rockauto. The thermostat uses RTV; I use Permatex Ultra-grey RTV. You'll also need coolant; any "universal color" coolant like Prestone will work fine, but I prefer Pentosin Pentafrost A2 green coolant, which is the same as the factory coolant, mixed 50/50 with a gallon of distilled water.
If you are replacing the water pump, you have to do it before you install the new belt as the pump is long and form part of the mounting area for the cover and you will not be able to get in on with the belt in place. You also don't want to get coolant on the new belt.
The most important thing is tensioning the new belt; too tight and it will "whine" and too lose and it will "rattle." Make sure you pay attention when you loosen and remove the tensioner as to what directly you turn it. Before installing the belt, you need to turn the tensioner (5.5MM allen wrench) to put spring tension on it and lock it down with the lock nut. Install the belt and once in place, loosen the tensioner lock nut, which allows the spring to move the tensioner pulley and take the slack out of the belt. Turn the passenger side cam sprocket a little bit counter-clockwise and the tensioner will take up the rest of the slack. Tighten the tensioner lock nut to 35 ft/lbs. Turn that same sprocket clockwise about the same amount, which puts the slack side between the two cam sprockets. With your thumb and forefinger placed at the center of that span between the two cam sprockets, twist the belt. You should be able to twist it 90 degrees. If you can't, it's too tight and if you can turn it more than 90 degrees, it's too loose.