1) Grab the OSX or Windows installer from the downloads page. Linux binary available too.
2) Check out the keyboard shortcuts.
3) Dump your samples and other files you want to load in /Users/<your_user_name>/vMPC/Stores/MPC2000XL. This is also where anything you save will be stored.
4) Report bugs and feature requests
MPC® and Akai Professional® are a registered trademarks of inMusic Brands. Inc. This emulator is not affiliated with inMusic and use of the MPC® and Akai Professional® names has not been authorized, sponsored or otherwise approved by inMusic.