Tune Your Guitar
In standard tuning your strings will be tuned to the following notes low-to-high: E A D G B E. There are other tunings, but don't bother messing with them unless you know what you are doing. Over 95% of all guitar music is in standard tuning or a dropped down version of it. Some guitar players tune all the strings down one half step.
Use the audio clips to get your guitar in tune to standard tuning. Match the pitch of each string as closely as you can. It's all right if it takes you awhile. You'll get better with practice. One you have tuned all six strings, go back and check them again. Sometimes you'll have to make some minor adjustments. Remember to tune up to the correct pitch and not down
Guitar Tuning Tips
The first thing you should whenever you pick up the guitar to play or practice is get it in tune. The sound of an out of tune guitar ranks up there with the sound of fingernails scratching on a chalkboard. It can be very discouraging to play an out of tune guitar, because nothing you play will sound right. In fact some beginners quit playing at all because of this very reason.
Tuning your guitar is something you get better at with practice. It takes time to develop your ears to the point that you are able to fine-tune your instrument. Once you have developed your "hearing power" you may hear subtle differences in pitch that you haven't heard before.
Always tune up. This means that you increase the tension of the string until it reaches the desired tone. If you go too far loosen the string tension and tune up again. This is much more accurate than tuning down and increases the chances of the string staying in tune.
To tune your guitar you'll need a reference pitch from another guitar, a piano, a tuning fork, or an electronic tuner. You can get a decent tuner at any music store for under $20. I suggest you get one if you don't already have one.