Using snapfish for printing

Having a recent interest in one of my photo's through redbubble, I have this lady who has specifically asked for a photo of mine to be printed and sent out to her on panoramic canvas. Two queries I have here, is snapfish any good to use to have this print done (print size: 50 x 100), the other, apart from finishing touches on photoshop, is there anything I need to do to the image to ensure it prints well, or is having a 10Mp image in jpeg saved at highest quality pass as satisfactory? Any thoughts out there greatly appreciate.

I am so excited that someone is interested in a print of mine, and not only want it on a large scale

And I would like to know the answer to the 2nd question as well.
I changed monitor, and now have to lighten all my shots in PS to get an acceptable print. Have fiddled with the monitor settings, but it's not right yet.
Just writing this down gave me two more ideas to try, so that's a good thing anyway.
Geoff

Have you calibrated your monitor? Also have you set set your printer to the ICC profile for that configuration (monitor/printer)? That may account for the difference.

The Photomonk

calibrate the monitor.

The other opton is to get a test print and see what happens....

I am so, but what has this got to do with the forum topic?

You could ask them to send you the colour profile of their printer if they have one.
I know a few shops here that do provide them and that way you can make sure the colours come out as they attend to be.