Watch the Electronic Tuner online guitar lesson by TrueFire from Beginner Guitar Explorations
Lesson Source: Susan Mazer's Hands-On Guitar: The Beginner's Guide
There are a few “musts” that all guitarists know. Try to keep an extra pick in your pocket, never leave your guitar next to the heater, and always be in tune. You can nail the song, but if you're out of tune it blows the whole piece.
Practice makes perfect with tuning up. We'll tune up together, and then you can try it on your own the next time you sit down to play. Buy an inexpensive chromatic tuner and it will become your best friend.