In the last beginner guitar lesson we learned the notes of the six 'open' strings E - A - D - G - B - E and some may wonder 'what happened to C and F?'. The strings on a guitar are tuned so that fingerings of chords and scales are 'playable' and to find all the notes we'll have to use the fingers of our left hand on the various frets.
Every fret corresponds to a Half Tone interval (see the Theory section) which is the interval between two consecutive piano keys, black and white.
So there is a half tone between B and C or E and F and two Half tones between C and D, D and E, F and G, G and A and A and B.
So, starting on the 6th string (E) we will find an F on the first fret, a G on the 3rd and an A on the fifth. This is also the pitch of the 5th string, so we can move to it and find a B on the 2nd fret a C on the 3rd and a D on the 5th and so on.
Obviously, seeing we have at least 20 frets, we can also go on on a single string and find all the notes on it and it would be a nice thing to memorize all the notes on all the frets.
It's interesting to see that we can find notes with the same pitch on different strings like the C on the 3rd string, 5th fret and the C on the 2nd string, 1st fret. It may be confusing at first but, actually, is a big bonus: it sempifies fingerings and scales in a big way compared to a keyboard instrument.
On the 'free' frets between the notes we find the 'black keys' notes, sharps and flats. On the 1st string 2nd fret we have Fsharp (F#), on the 4th G# (or A flat, it's actually the same pitch) and so on.
This concludes our lesson on notes: the next step is to learn about chords.