While most profile's are used with explicitly ICC aware applications like Photoshop, you can use profiles with application without the option of specifically choosing a profile in the printing dialogue.
Here are some notes on using profiles with iPhoto. This method should be the same for all applications on a Mac, in principle. Incidentally, you can follow much the same approach on the PC by associating a profile for a printer in the 'colour management' tab of the printer properties.
The process of printing my files for the exhibition was made very simple with all the detailed information on the Image Science website. In particular the downloadable templates are a fantastic resource. I feel I have a pretty good basic knowledge about the printing process and pre-production but I am totally in awe of the knowledge and set up at Image Science. Printing with them I feel in safe hands and very happy with the final results.