Get Your Guitar In Tune
Tuning is an important skill to learn but takes practice just like everything else, so I do advise beginners to get a guitar tuner so they can make the guitar sound as nice as possible, for you and anyone that has to listen to you practise!
I have a whole series that explains the different ways to tune your guitar, so check it out:
Tuning to a tuner
It's my opinion that beginner guitarists should use an electric tuner. Learning to tune takes some time and I think it's better if a student has some time to hear a guitar in tune before starting work learning to tune themselves. It's also a lot better for those that have to listen as well! We sell some cool ones on the justinguitar store too! ;)
Tuners are not expensive these days and there are some brilliant ones available as iPhone apps now. I mostly use clip-on tuners, specifically the TC Electronic PolyTune Clip, but it's not cheap and the D'Addario ones are good enough for beginners and cost a lot less - so depends on your budget.
Tuning to reference notes
Using reference notes to tune is a very useful skill and one you can learn during this course using the tuning notes found in the. To use this method, listen to the reference note and then tune the corresponding string up or down to match. It will take some practice to be able to do this quickly and accurately, but it's a skill you will find useful if you want to play with another musician (especially if they can't change their tuning easily, like piano players!).
Tuning to a piano
Tuning to a piano is the same as above really, but instead of using a reference track on a CD of another guitar, you play notes on a piano. You will learn the notes of the open strings on the guitar soon (so you can ask a piano player to “give me an A”) or you can use the chart to play them yourself. The thinnest string is the pitch E above ‘Middle' C. (Hint: hold down the sustain pedal under the piano so the note rings out after you have taken your finger off the key to tuning your guitar!).
Tuning to pitch pipes
Pitch pipes were what I had with my first guitar! They are like a harmonica but they only have six notes, which match up with the six strings of the guitar. They are popular because they are small, cheap and you can hold it in your mouth and blow while you use your hands to tune up... but I still think getting a tuner is a better option.
If you don't have access to a tuner or any other reference to tune to, you can use this method to get your instrument in tune with itself. Because most notes on the guitar can be found in more than one place on the neck, it is possible to use to tune quickly and quite accurately using this method - but you probably won't be at 'concert pitch'.
Tuning with harmonics
There is one more advanced tuning method commonly used and that is using harmonics, it's not really suitable for beginners because it requires some techniques not covered in the beginner's course, but you can find it in the Tune Your Guitar module