Pro-96 is a great scanner, especially when someone gives you one
As for programming, you will need 2 things: PC interface cable available from RadioShack and a program called Win96 (free for 30 days). I have a P96 data file for Riverside County that you are welcome to use and modify to suit your needs. Good luck.
Using Pro96
Re: Using Pro96
Since you are using a USB-to-Serial converter, the COM Port won't be the default value (COM1) in Win97. I would try using COM3 and see if it works. If that does not, you may want to go into the Hardware Manager and view the setting. To find the COM port just right click on "My Computer", choose Manage and then go down to Device Manager and look under the Ports (COM & LPT) option on the right hand side. It will display the COM port # (make sure you converter is plugged in). To change the COM port inside of Win97 just open the program and go to Configuration -> Serial Port and you can select the right value. Good luck.