In this lesson, I'm going to teach you how to tune a guitar.
Before you can tune however, you need to know the open tuning of the 6 strings.
ANOTHER DAY GOES BY
Remember that phrase. Memorize it! You'll always use it, I promise. It is the best way to remember the open tuning of the middle 4 strings, starting with the one closest to you when holding the guitar.
The outer two strings (the lowest and highest strings) are both E; easy enough to remember.
TUNING BY EAR
Learning to tune by ear is a great skill to have. You never know when the day will come that you want to play the guitar and there's no tuner around to help you. Or you're in the middle of playing and notice one string slightly out of tune. Instead of going through the hassle of pulling out a tuner, this method is much faster and more efficient.
The basic idea is that the 5th fret of one string is the same note as the next string in open position (without pressing down on it). That is, with the exception of the G string, which needs the 4th fret pressed in order to play the B for the next string. And it's really as simple as that. Memorize this pattern, and you'll be able to tune by ear.
That being said, keep in mind that there's no way to tune the low E string without some outside source. So though you can get your guitar in tune with itself, it may or may not be in the correct tune with the rest of the world.
USING A TUNER
To get your low E string in tune, or all of them if you rather, you'll need some type of tuner.
There are many great phone apps out there that will do the job. The one I recommend and that I use is "guitar tuna". It is very accurate and has a great user interface.
As far as hardware, I use the KORG pitch clip, which clips to the head of your guitar and uses a color gauge to indicate the pitch of your strings.
Regardless of what device you use to tune your guitar, all of them work relatively the same. The note being played will be shown, along with some type of gauge to let you know if the note is sharp # (too high) or flat b (too low). And you'll use this information to turn your tuning knobs accordingly. Once you understand the basics, you'll be able to read any tuner.
I hope that helps you out. Good luck, and let me know if you have any questions!