2004 xterra would sound sluggish when cranking. Similar to the sound a car makes if timing is off. Belts are fine. And put new battwey and terminals. Cranked fine dor two to three rimes but started doing the sluggish crank. Finally it quit turning over at all. All the lights work and the headlight dont dim when trying to get it to crank. What would be my options for dyi. By the way, the voltage on battery is perfect.

Many new timing belts have alignment marks on them that would be very helpful for you

Before you spend a penny on it try jumping from a good vehicle. Does it turn as expected? Yes? Then check your battery.
No, then check the leads and ground cable to the battery and chassis.
At that mileage I'd expect the starter to be on the way out. Its drawing heavily on the battery because its worn inside. Hence the poor cranking speed. Don't worry about plugs belts etc until you have sorted the starting part. Get a good home mech to help.

dont drive iwith missfire, its not ecm ecu problem

Have your temperature sending unit/sensor checked for proper operation, it may not be working and not placing the engine into cold start mode so it will start easily. This is like the old style automatic choke that's stuck open.

YOU COULD HAVE LOOSE CORRODED BAD BATTERY CABLES. FAULTY STARTER. BLOWN STARTER FUSE. REMOVE STARTER BENCH TEST.CODE SCAN FOR THEFT SECURITY FAULT CODE OR YOU HAVE BAD CLUTCH SAFETY SWITCH OR CODE SCAN FAULT CODE FOR TRANSMISSION PARK NEUTRAL POSITION SWITCH OR TRANSMISSION RANGE SENSOR.

The only cure to fix squeaking belts, is to replace with the new one. When the belts start squeaking noise, then it is the time to check the status of the timing belt or chain, depending on the size of the engine.
The 2000-2004 Nissan Xterra was offered with the choice of 2.4L 4-cylinder or 3.3L V6 engine.
The 2.4-liter 4-cylinder DOHC engine was a pretty good reliable engine, but for this truck, it was underpowered. This engine has a long-lasting timing chain - there is no timing belt to replace.
The 3.3-liter V6 SOHC was also a bit slow on pick-up, but for daily use, it was pretty good, durable, simple engine. This engine has a timing belt that needs to be replaced at recommended intervals. The SE model offered a supercharged version of the same engine with more power.
To get more information, please read my tip :
When should I change the timing belt on my car?
http://www.fixya.com/cars/r6481199-when_change_timing_belt_car

It sounds like you have loose belt(s). When the A/C is turned on, it puts a big load on the belt, if it is loose and starts slipping and squeeling, then the alternator won't turn, so the battery runs down as you drive. Make sure all your belts and battery terminals are tight.

Check and make sure the battery is good,have it load checked,then check the battery connections to make sure they are clean and shiny.No grey or black residue on the battery connection,or the battery terminals,where they go on the battery,this will act as a insulator,and the battery will not get charged up enough,or put out enough amps to crank the vehicle,if it still does this ,with all this checked and corrected,then the starer is defective,replace the defective starter with a new one.

Timing belt ever been changed? Sure does sound like the problem. An old belt will snap on a cold start. Might want to look to see if the belt is tight and in place. These belts break regularly on Hondas with over 70,000 miles on them. Timing Belt change interval is 50,000.

sounds to me like the thermostat may be stuck. i would check the coolant, fan, and belts.