I have had an M1 Carbine for several years but don't know much about it.  On the front top of the receiver it says "U.S. Carbine Cal. 30 M1" and on the back of the receiver it says "I.B.M. Corp 39542xx"

I'd appreciate any info on quality and value of this carbine.

International Business Machines (IBM) was a WWII era contractor for U.S.G.I. M1 Carbines. The quality is top shelf. Value depends on a lot of variables. Is it an Import? Many M1 Carbines were "re-patriated" during the late 80's/early 90's. Look on the barrel for markings such as "Blue Sky" or "Arlington" Look closely on the sides or underside of the barrel. Imports have less value than non-imports.
Look for manufacturers markings on all major components as well. Is it in original WWII configuration or does it have the post WWII era modifications such as a bayonet lug and three prong Mag catch? Is the stock/handguard original to the rifle? Does it have Ordinance Dept. Cartouches?
Give your carbine a thorough inspection using a light and magnifying glass. Note all of the markings on all of the components. Post the info in the Carbine forums here www.jouster.com and here www.battlerifles.com Culvers has many knowledgeable Carbine collectors who are willing to share their experience.
Value of U.S.G.I. Carbines ranges from $350.00+ for a worn out import to $500.00+ for a very good condition import and $500.00+ for a worn out non-import to $1,000.00+ for a pristine non imported U.S.G.I arsenal rebuild. Like new factory original Carbines and original M1A1 Para-trooper models go higher. Often much, much higher.