Your best bet is to buy/download a copy of scanner programming software that will read the database and then drop it into your scanner.
I do not own a 996 model, but ones like it have a little learning curve. The best I can advise you is what I wrote above and to play with it. Crack out the manual... you'll learn a lot of neat tricks and it will help you program stuff in down the road as you figure out the roadmap.
Also check out the Uniden Fourm on here and this one... lots of good information:
Software - The RadioReference.com Forums
The other answer, is to program in the control channel(s) of the sites local to you, scan in the control channel mode, and program in the talkgroups you want to listen to. Its a multistep process (hence break out the manual) but once you figure it out, its comes pretty easy.