Hello DJM
If you are just venturing into the world of printing your art then yes take it to a print shop an have them do it for now.
Find out which image format/s they prefer to work with. Most likely it will be one of the usual suspects i.e; tiff, pdf, png, jpeg.
Note; A print company will not be able to use the native ArtRage .ptg file format.
As for resolution well it all depends… But again for now a good rule of thumb would be somewhere around 300dpi/ppi.
Getting digital stuff out into the real world exactly as we would won’t it to look can be very easy or very complex! It all depends on our expectations and/or requirements!
As a starting point in understanding all this have a look at Tutor Tanith’s site. It provides quit a good introduction to the perils and pitfalls of bringing digital art into the real world and what you need to bear in mind when creating your art.
The sections you will want are the ones on Image Size and Image Colours.
Size:
http://www.tutortanith.com/imagesizing.htm
Colours:
http://www.tutortanith.com/imagecolor1.htm
(and don’t miss the further links on Size & Colour at the at the bottom of those pages!)
Expect some initial print disappointments as you’r starting out but as you learn they will soon get fewer and fewer!