I picked up a few things from there.
- Press F7 for a previous command list.
- View all environment variables: SET
- View only system variables that start with W: Set W
- Find what process has opened what port: netstat -noa
- Widen your command prompt: mode 120,100
- View your TCP/IP settings: netsh interface ip show config
- Weird looking colors: color 8f
Also, check this out if you need a better command prompt.