There’s no reason to study the fretboard until after you’ve learned the very basics, like chords, a few barre chords, picking, strumming and easy songs. But once you do, your level of playing will start advancing in giant leaps.
Understanding the notes around the fretboard and their relation to 1 another is your initial step in studying guitar theory. Once you are familiar with the notes, studying to form chords, playing scale shapes, and even writing music will seem easy and effortless. Of course it takes time, patience, and lots of studying, so lets just stick to the notes around the fretboard for now.
The initial step in learning the fretboard is to remember the notes along strings five and six. Focus on the natural notes, so leave out the flats and sharps for now. The natural notes are the letters A thru G and usually occur in alphabetical order. The second step would be to fill the gaps with sharps and flats. Sharp (#) indicates 1 fret higher while flat (b) indicates 1 fret lower.
Watch the video, and download this free fretboard training software if you want an interactive studying experience as well.