Chris Dodkin posted a basic colorspace workflow on the FM Forums:
1) Set color space on your camera - choose a full gamut color space such as Adobe RGB - shoot RAW to avoid your camera making the color temp decisions for you
2) Calibrate your computer monitor - start HERE
3) Set default color space in Photoshop to match the camera, so Adobe RGB in this case
4) Import RAW file into photoshop, making decision on color temp etc
5) Edit image and store as PSD file to avoid any image compression or data loss
6) Assign image the color space profile from your chosen printer (downloaded from Drycreek)
7) You can compare the new image against the stored Adobe RGB version, either by flicking backwards and forwards in PS, or comparing it with a previous copy.
You'll see the color of the image with the printer color profile assigned has changed.
8) Use curves and other color balance tools in PS to modify the new file to get back to the color of the original Adobe RGB file
9) Save the modified file as a lossless TIFF with no color profile embedded
10) Take the TIFF to the lab - upload and tell the staff 'PRINT WITH NO CORRECTIONS ON THE CALIBRATED PRINTER'
11) Collect your print and marvel at how it looks just like the image on your computer screen
Far more detail @ DRYCREEK