And as a preemptive strike...
You need to make sure you have the Korg padKontrol devices drivers installed properly (download the most recent ones for YOUR system setup/OS version directly from their site... not the disc).
You NEED to make sure the padKontrol is connected and turned on BEFORE opening Sonar otherwise it will not be detected or respond to input (at least that is the case on my system). I usually wait a minute after turning it on before opening Sonar if I intend to use it.
In Sonar Preferences you can treat it just like any other MIDI device. Go to Edit > Preferences > MIDI - Devices and make sure you select ALL the padKontrol entries.
There are TWO MIDI ports coming from the padKontrol. Port A and Port B. IIRC Port A is what the pads transmit from and Port B is what the two knobs at the top transmit from so make sure they are all selected in your Sonar Preferences and as you set up the controller to do stuff in Sonar make sure you keep that port separation in mind.
As far as programming the pK internally that is all detailed in the manual (which admittedly is quite confusing) but basically you need to choose a "Scene" and engage the "Program" mode, tap the buttons to enable them for programming (like setting them to a specific MIDI note) then turn the appropriate dials to Choose the note for that pad, then repeat for the rest of the pads in the scene. Then you save the scene.
You can also set velocity sensitivity and a bunch of other crap that way... for every pad... in every scene... and you can save ALL the internal scenes to the "Editor" software if you want and dump/reload all that info whenever you want (internal memory on the device allows 16 "scenes"... the Editor Librarian software is nly limite by your computer storage space... so unlimited).
So yeah... what exactly are you trying to do?
If you just want to put on a silly lightshow with the pads... well I am unlikely to even WANT to help with that but there are vids to do that stuff.
For true MIDI control programming then I'll help how I can.
I use it to play drums through my drum sampler programs and other wackiness so have study it to an intermediate level.
Cheers.