ram965:
Welcome to the Forum. I second shadycon's advice. I believe you can go to Amazon.com and buy 'U. S. M1Carbines, Wartime Production', 7th Edition, by Craig Riesch, for less than $20 delivered. In my opinion this book is the best bang for your buck (less than a round of beers) to identify the original component parts in a carbine and give you a little history and general knowledge of carbine development and variations. It has a few errors (all references do) and is not as comprehensive as War Baby ($60-$130 per volume), but for the price it is terrific. If I were just starting out and could buy one book, Riesch would be the book (as a matter of fact it was my first book).
'The M1 Carbine Owner's Guide' by Ruth & Duff is also a good book at about the same price as Riesch. It offers less detailed parts description and more operation and maintenance instruction than Riesch, and includes tables of manufacturre dates by serial number. The manufacture dates published are approximate and somewhat arguable because (with exception of Winchester) there are no written records of monthly production of the carbines. War Baby or the Carbine Club are more reliable sources for approximate manufacture date of a carbine but Ruth/Duff gives you a starting point.
Anyway, if you buy a carbine get a USGI carbine. Every one of them was manufactured during WWII. They cost about the same as, or less than, a newer commercial copy and, as noted by others above, they are made better, work better and will appreciate far more in value than the commercial copies as time goes by.
Warning - you will probably not be able to stop with just one carbine and it will get worse with each one you acquire. But that's your problem - we all have our own!!! Good luck. ChipS