First you need to decide which tower sites you are closest to and add those Control and alternate channel frequencies. Then you'll need to find the Talkgroup ID's that you want to listen to within the system.
Go to this link and find the tower sites near you, then input the frequencies highlighted in Red and Blue into your scanner. You'll have to scroll down a bit to find them.
http://www.radioreference.com/module...=TRSDB&sid=100
Then scroll down until you get to the listings of Takgroup's for MSP and pick what you want to listen to. Input the 4 digit number from the left most column into your talkgroup ID banks.
Rob