Create a new playlist in iTunes (File->New->Playlist or Ctrl-N)
Name the playlist if you want e.x.: Disc
Click on the Songs section of your library in the left column to see all your tracks.
Drag songs from the right side of iTunes and drop onto your new playlist
Click on the new playlist and see how many songs you have and the time in the status bar at the bottom (No bar, View->Show Status Bar or Ctrl-/ will make it appear) ensuring you are under 99 songs and 74 minutes for a standard audio CD.
Right click the playlist name in the left column, choose Burn Playlist to Disc
Select your Disc format (Audio, MP3, Data) if using Audio, typically you would check Gap Between Songs to add 2 seconds of silence between tracks.