for basic spot color work, your Color Mode (RGB or CMYK) won't matter much. Let's say you had a circle that is red, and another circle that is green. The red or green should be saved as a spot color. PMS colors from the Solid Coated pallet are spot colors, so you could simply assign one of those. Or, you could pick a color off the default pallet, and double click on it, and there is a drop down menu that will let you change a color from process to spot. Now, when you go to print, and click on "Output" you'll get a list of colors to print; shut off (no printer icon)the 4 CMYK channels, and you'll be left with just the Green and Red you chose. If you have 1/2 tones, you can select your line count and angle to be set in AccuRIP, in which all halftone seps will use those settings, or, you can set them in Illustrator (in case you want a special line count and angle). Hope this helps. There are a ton of decent tuts out there...
Steve
