The guitar standard tuning is as follows:
STRING - 6th String (bottom, bass, low) NOTE - E
5th String - A
4th String - D
3rd String - G
2nd String - B
1st String (top, treble, high) - E
Tips For Any Guitar Tuning Method
First, lets cover a few things that every player should know when taking the proper approach to guitar tuning and how to learn to tune guitar.
Learn to attach the strings to the machine heads properly. Never try to tune down to a note. Stretch the strings and tune up to the note. Tuning heads have a certain amount of 'play' in them so make a couple of deep bends and then fine tune the string. Before tuning a suspect string, check it against both adjacent strings to determine which string is actually out of tune. The string you suspect may not even be the culprit. When tuning a guitar with a vibrato arm, tune the string, give the arm a good shake, stretch the string, give the arm another shake and fine tune.
Veterans of guitar playing will already know these things so if you're a beginner and just learning to play the guitar, you're already ahead of the game if you implement these practices into your routine. For a great tool visit http://www.guitarmusician.com/guitar-tuner.htm
Here's A Quick Method For Guitar Tuning
Tune the treble (high) E string to an A440 tuning fork by holding your finger on the 5th fret, then tune the open B string to the open treble E string – listening to the interval of a fourth. It's easy to hear the fourth in that register.
Play the A note fretted at the 2nd fret of the G string, and compare it to the open treble E string – you're listening for a perfect fifth interval.
Fret the 2nd fret E note on the D string and compare it to the treble E string open. Double check this by fretting the E note on the 14th fret of the D string.
Now tune the 7th fret harmonic on the A string (an E note) to the open treble E string.
Finally, tune the 5th fret harmonic on the bass E string to the open treble E string.
This is a simple guitar tuning method that works well.