With a 536 (and most scanners with on-board system databases), you really don't need to know much about programming - at least not at the start.
Things you will want to do - if you haven't already:
1. Install Sentinel on your PC
2. Connect your radio to the PC and check for both FIRMWARE updates and DATABASE updates.
3. Disconnect your radio from the PC.
On the radio (after it boots up):
1. Press the SERV button and select the types of things you might want to hear
2. Press the ZIP button and set your zip code
3. Optionally: Press the RANG button to reduce the distance out from your location to try and scan (I think the default is 20 - you may want to experiment with smaller ranges).
Scan for a bit...
If you hear things not of interest or things that the radio "sticks" on, simply press the AVOID button.
You can get into more specific and detailed programming after this is done.