Entering into the print market isn't as easy as I thought. There are so many options to choose from I had to really do my research. I recommend working with a local company that scans or photographs original artwork into high resolution photos for printing. Make sure to ask for both RGB and CMYK files, depending the printer you will be glad to have both. If you're in Nashville, TN this is who I recommend:
If you plan on printing fewer than 50 prints then it might be more cost effective to go digital. Almost anywhere will print digital images. Walgreens, Kinkos, Wolf Camera, etc. If you want a professional product, then hire a professional printing company.
I recommend Wondergraphics, www.wondergraphics.net. I tried a hand full of printers before I made my decision to stick with them. I have been very happy and love working with the people there!
If you need to print more than 50 than go commercial and mass produce with offset printing. It's a pretty cool process. Visit www.uprinting.com for ordering information, it was a great website.
Giclee is another option for printing. If you want to give your collectors an investment than go with Giclee. The inks will last a few lifetimes and can be printed on canvas or paper. Check out www.allpconline.com for more information.