Sorry HiTek21, you're absolutely wrong. A USB mouse has an extremely high DPI compared to a PS2 mouse, which increases response and precision. You are much better off using the USB.
As for the Microsoft Natural Pro Keyboard, the cord has a USB plug which runs power to the hub built into the keyboard, so plug your keyboard into the USB on the back of your computer This hub is very useful for many pieces of hardware. Its unpowered, but will still work for digital cameras, flash drives, mice etc. If the hardware already has its own AC adaptor like a PDA or printer it will also work off the keyboard just fine.