Open the program and go to "Insert" on the top menu bar, and then "Audio Track" to create up to 5 tracks. Plug the microphone into your computer's sound card through the "Mic" or "Microphone" port.
"Arm" the track for recording by selecting the "Arm for Recording" button in the "Track Listing," which is indicated by a red bulls-eye. Set the "Record Settings" to "Stereo" by clicking the "Record Device Selector" to the left of the "Arm for Recording" button" in the "Track Listing."
Turn on the microphone, then click the "Start" button located at the bottom left hand of your main screen. Select "All Programs" then go to "Accessories" and then "Entertainment." Select "Volume Control" from the list of options, and make sure the "Microphone" box has a check next to it.
Click the mouse on the program "Audio Timeline" at the place where you wish to start recording. Click the "Record" button on the "Transport" bar located at the top of the screen. Record the vocals or instruments you wish to record through the microphone. Press the "Stop" button, located at the top on the "Transport" bar, once you're done recording.
Repeat all above steps on different tracks to add more vocals or instruments. Save the mix by selecting "File" then "Save" on the top menu bar.