Way too much experience....

For printing large, you need large photos (duh)
Mine were usually a good 48in wide and 60in tall.

First thing, have the images at the desire print size, at a min of 72dpi.
-The printer should scale it up to 300dpi, with no distortion on the final product.

Next, decide what you are going to print on. Pearl finish, 100# paper, canvas, linen, to name a few.
-Each paper will need to have different settings; more dry time, more ink, ect...

If you have the money, get them backed by the same company that does the printing.
-this will be a lot easier than doing it your self.

A protective coating is a must!
-its usually pretty cheap, a few dollars at most

Your probably looking for standard 100# paper, with a ridge-board (foam board) backing, and a protective coating on the front.

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As for personal experience, A client of mine has an Epson 9600, and he let me do my printing for free. Its takes a bit to get used to, calibrating for different papers and inks and so on. They come out rather nice, but having someone else do it professionally is a lot nicer.

I used canvas and 80# - 120# paper
Printed with standard and chromatic inks
And used clear coat spray paint for my protective coating.
Usually matte or foam bored for the backing.

Check out Mpix (http://www.mpix.com/) for an idea of price and such...

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