Some helpful hints for new M1 owners:
As mentioned above, use a good grease to lube the M1, but use it sparingly. As Brian said, a little dab will do ya. In addition to Super Lube, Plastilube is also excellent and was the standard in my rifle team shooting days with the M1 and M14. This can be bought from Champions choice or can occasionally be found in the little pots with the yellow lids at gun shows. If the grease is dark amber colored, it's Plastilube. If it's cream colored, it's Lubriplate.
Install a brand new op rod spring in the rifle. The rifle will be a bit softer recoiling and snappier with a new spring. Fulton Armory tracked down the original contractor and is having newly made springs to the original print made for them.
Don't forget to grease it before installing.
The wood to metal fit is the single biggest reason an M1 either shoots well or not. Clamping pressure is the most important. If you don't have it, it's like shooting a bolt action with loose screws. Improving the clamping tension can be done in several ways depending on the rifles particular deficiencies. If you want to try to do the work yourself, we can discuss your rifles needs and help you get there.
Unless the barrel looks like a sewer pipe, or has a badly damaged crown, I wouldn't consider replacing it until the rifles other deficiencies are addressed and the rifles accuracy potential is evaluated with good ammo. The best shooting M1 I have has a throat erosion reading of 5. More importantly, it doesn't walk it's shots as it heats up, which is important for match shooting.
If you don't reload, Both Hornady and Federal have ammo specifically loaded for the M1. Greek Ball ammo is also still available from CMP and other sources. Do not shoot modern commercial ammo in the M1. The powders used today generate excessive port pressure and are very hard on the op rod. Eventually, you will bend it.
If you do reload, read up on the things you need to do that are specific to loading for the M1. I've made a post on another forum that can be C&P here if there's interest.
If after a good scrubbing with solvent and a stiff nylon brush you are not satisfied with the condition of the parkerizing, consider doing it yourself. This is a very simple process that can be done in your back yard. I can make a thread about that too if needed.
And some folks may not be aware, but CMP has a repair service for USGI rifles. Rebarrel/repark/restock. Whatever you need. They also sell parts.
Here's a couple of threads pertaining to the M1.
How To Improve an M1 Trigger
How to Make an M1 Shoot Better
