MIDI:Assign different sounds to drum pads?

This is my first time using midi and i'm having trouble figuring out how to assign different sounds to the drum pads while playing a different sound on the keys.

I am using the Akai mini mpkII, 25 keys with 8 Pads all velocity and i do have the midi editor downloaded.


I would also like to be able to use the drum pads to play different parts of a sample.

Any help is appreciated!