What parts needed to be oiled and is there any parts that does not need oiling as it may just attract more grime and dirt? Should I oil the part of the bolt that goes inside the bolt carrier and the bolt seals? how about the trigger assembly? thanks.

Put a small drop of oil on the ejector plunger.

Before putting the bolt into the bolt carrier, place a drop of oil on the gas rings, a drop on the cam pin.  

Do NOT oil the firing pin.  In fact, when cleaning, there is a good place to use those damned pipe cleaners... through the firing pin hole in the bolt.  Clean that out.

A drop of oil on the extractor back where it hinges on the extractor pin.

After assembling the bolt carrier, hold it vertical, and two drops down the gas key.  Then turn it on its side, and while working the bolt back and forth, a drop in the weep holes.  Work this around.

You CANNOT overoil here, as excess will be blown out the first time you fire.

While I wipe the whole bolt carrier with a thin film of CLP via an oily rag, it is not necessary to heavily lube it.  The bolt carrier rides on four "rails".  You see the four shiny spots?  

Wipe out the upper with a slightly oily rag, but  leave it almost dry.  Put a drop of CLP on each of the four "rails" on the bolt carrier, and smear it along the rails with your fingers.  Spread a few drops of oil on the lugs of the bolt.

Wipe the charging handle with the slightly oily rag.

Put a drop of oil on the outside of the Forward Assist, and work it in by pushing the FA.  Push it in, and from the inside, drop some oil there, too.  Unless you have thoroughly degreased your upper, which is not necessary for every cleaning, it should not be necessary to relube it every time.

Now assemble the charging handle and bolt carrier assembly into the upper, and move it around to spread the lube.

On the lower, a drop of oil in the detent groove of the front pivot pin, and the rear takedown pin will easily wick back to those detents.  Put a tiny drop of oil on the buffer retaining detent, one on each side of the safety/selector.

Put a drop of oil on the hammer and trigger pins  from the inside, between the hammer and lower receiver on each side, and the trigger and lower receiver on both sides.  With the hammer up, the fired position, put a drop on the hammer sear.

On the outside, a drop up on the front sight plunger will wick in and keep that from rusting up.  Also lube the rear sight assembly.  Wipe the rear sight blade and front sight pin with a Qtip dampened in oil.  Wipe down the barrel with oil dampened rag.  Make sure you remove the handguards and wipe down under there, too.  Get the inside and outside of the front handguard cap.  These are prone to rusting if left dry.

Occasionally oil the dust cover pin.

Occasionally remove the buffer, wipe clean, swab out the receiver extension (buffer tube), wipe the spring down, reassemble and drop a few drops of CLP around the buffer.

That should do it.

Did I leave out anything?

Thanks very much!! That was very informative. Except that i dont know how to remove the handguards. i am afraid that I may not be able to put it back!! Thanks.

You can download the Bushmaster or TM 9 manual with full pics and everything at [url]http://www.ar15.com/content/books/[/url]

What fight4yourrights said. This one
TM 9-1005-319-10 is the bible for operators. The hobbyists have their own opinions.

Locking lugs.

"Wipe out the upper with a slightly oily rag, but leave it almost dry. Put a drop of CLP on each of the four "rails" on the bolt carrier, and smear it along the rails with your fingers. [i]Spread a few drops of oil on the lugs of the bolt."[/i]

Enough will get in the locking lugs in the barrel extension from the oil on the bolt lugs.