A crossover cable is a LAN (local area network) cable designe to connect two computers together without needing to use a Switch or a hub or a router. The wires in it "cross over" so that each machine can send and receive ove the cable. Just ask for one at the computer shop, they'll know what you are talking about.

Well wireless is horribly insecure unless you use encryption, the best for home use is WPA2/PSK with a 32 character key, I just generate a 32 character hexadecimal number, and use that.

Wireless mouse and wireless keyboard use a different wireless protocol to WiFi, which is built around the 802.11 standard. wireless mouse and wireless keyboard have a range of about a meter or two, and are perfectly safe from eaves droppers, unless they manage to be in the same room as you. You are more likely to have a key logger virus infect your Windows Operating system than you are to be compromised via wireless mouse and keyboard. I dislike them because they are unreliable.

The [network] cable connects to the computers network port, which is an RJ45 type connection built into the computers network card (which may in turn be built into the computers mother board). As you already have a hub, you must already have a Local area network, so you don't need to get a switch, or a router, you already have a hub, and i have to assume both machines are already connected to it via network cables. Which means you already have a network. So simply following the instructions I linked to, you should be able to set up remote desktop on the windows machine. There should also be an application on the Mac for accessing a Windows via RDP. Anything from 10Mb and up is sufficient for a remote desktop session. In fact we do it across the internet, and the internet is considerably slower than a 10Mb hub.