A classical guitar is tuned; E, A, D, G, B, E starting with the low E (thickest) string. To start tuning your guitar strike the tuning fork against a hard surface, that is not your guitar.
Place the balled end of the tuning fork against the sounding board (face) of the guitar. This will act like plucking the string and the guitar will resonate the tune.
To make the tuning process a little easier, move the tuning fork around on the body of the guitar until you find the loudest spot.
Now, pluck the High E (thinnest) string of the guitar. This string should sound the same as the tuning fork. If it is not the same adjust the tension on the string by turning the peg. Loosen the string to lower the note. Tighten it to raise the note.
Now that you have the High E tuned in you can continue on. To tune the next string up place your finger just in front of fifth fret. This is also the “High E” note, and should sound just the same as the bottom string.
To Tune the Thrid string up place your finger just before the fourth fret. The note that you play here should be the same as the second string being played open.
From this point up you play the fifth fret on the next sting, and it should sound the same as the string below it being played open.