I have a document header in a single color (red) that I need to convert to "1/color" - not sure what that means but my question is how can I do the conversion in photoshop?

Thanks a lot !

IFrom the date of the original post, this may be to late but we should make this a mantra in a Typesetting forum -
Never Set Type In Photoshop.
The basics of file size and resolution dictate this.
Excepting headings, where one just has to have a specific effect, Photoshop is not a typesetting program.
Can you get a spot color? sure. The easiest and most reliable would be to create a grayscale image and apply a spot color in the page layout software. If you needed to utilize PS, understand that a color is a channel and read the PS help in regards to spot channels. Create a spot channel, work in that channel with the element, and save a DCS eps file. Depending on your version of PS and the recipients software, this will raise some eyebrows at the least. (Expect them to try to open the file in Ilustrator and inform you that the eps is corrupt)