We'll give it a little boost at the end, but you don't want it to be too quiet or so loud that the waveform jumps out of the window and distorts the sound. Make sure the recorded volume sounds (and looks) OK. Hit the Stop button in Audacity once you're done and then play the recording back over some connected headphones to check the quality.

Before committing to recording a whole side, hit play on your tape deck and record 30 seconds of audio into Audacity using the application's Record button.