There are three basic kinds of wireless mice.
- desktop models, mostly come with a transceiver attached to the USB port, runs on batteries, and is basically a replacement for a normal wired mouse
- notebook models, usually smaller but otherwise similar to the desktop model. Often has a much smaller USB transceiver and often this attaches to the mouse for storage. These will work for desktops as well, but are often a little smaller.
- bluetooth, this relies on the built-in bluetooth transmitter in your desktop/notebook so it requires no additional wires. If you dont have one, dont get this type.

For desktop mice, you can get them with/without keyboards. That's up to you. The keyboard is wireless as well and comes with a transceiver with 2 wires that take up 2 USB ports on your machine (sometimes they come with adapaters for the DIN ports on your desktop). The big three brands are Microsoft, Logitech, Kensington.

I like the Microsoft mice better than logitech. Just a personal choice, I've tried a few different ones. But a store like CompUSA or Best Buy have a bunch on display to play around with.