If the work is done at a pro shop it is most likely that you will end up with a "Kodak Photo CD" not to be confused with a "Picture CD" commonly available at drug stores, etc. The quality you will get from the Picture CD depends entirely on who is doing the work, usually they are very good. Kodak uses a proprietary format which returns an image which can be opened in the computer in a variety of spatial resolutions up to 2000X3000 pixels for full frame 35mm. There is also available a Professional level Photo CD which returns even higher resolution but that is pretty expensive. Photo CD is a good alternative to doiing your own scanning and is usually much higher quality than Picture CD which returns a low resolution JPEG and is only available for rolls that have just been processed.
Hope this helps.