Good advice there. Really, the biggest things to have with any stain removal process is a mild liquid detergent (like Ivory dish soap), distilled white vinegar, cold water, hot water, lots of paper towels and hydrogen peroxide.
With your particular situation, I would agree that water rinsing is the most important thing. If you can catch a urine spot within one hour of it happening, you can get it completely clean with some soap and water. After an hour, it turns alkalyn and you'll need vinegar to neutralize it. You can then use some hydrogen peroxide to remove some of the yellow staining.
You can also call a local certified carpet cleaner. Carpet cleaning companies (like mine) also clean upholstery, and we're experienced in getting organic stains out of fabric. You may only need deodorizing, though usually if there's an odor, there's also some protein matter left behind, so keep that in mind. If you need to contact a carpet cleaner in your area, you can visit our site, which is specifically made for carpet and oriental rug cleaning in Greensboro, NC. But, you can read up on the process and visit some of the links on the site to find cleaners in your area.
http://www.zimmermancarpetcleaners.com