Also if your looking for a Radio Shack scanner the Wiki is a good start, also talk to Abqscan (Eric) who works for RS. Below is the link to RS scanners look under the trunk tracking colum and look for the P25.
At least you found this website! The people here in the Colorado Forum are VERY helpful and will get you going once you get the right scanner! We also have fun get togethers and are able to help each other out. I would highly suggest looking at someone elses file for a programming software and get an idea, and then customize it to suit your own needs. Programming a trunking scanner by hand is extremely difficult so I suggest you look into the software, and you can easily import what you want from this website. The State DTRS system is quite complicated but they have made it easier, so check out the wiki and the coverage maps to get an idea what sites you need for your area.