Ahh...two simple words, "Music Theory," can make some guitarists/bassists run faster than if you'd yelled, "Fire!" True, much of theory study is dry. However, if you expect to advance to the next level in your playing, some knowledge of basic theory is required...sorry. ;)
This is where learning...MEMORIZING...the Circle of Fifths/Forths comes in. The COF's is not the be-all/end-all for music theory...but it's a HUGE start...ask any music major! Learning...and understanding...the COF will improve your overall musicianship...period. Combining this with a quick excercise daily will also help you learn ALL the notes on the fretboard.
So, what's this circle thing? Without getting into a ton of detail, the COF is an excellent tool for learning key signatures, common chords, relative minors, and a ton of other stuff.
Entire lessons could be written on the various uses of the COF. However, I don't want your eyes to begin glassing over...so I'll provide an off-site link for those of you who want to learn more.
Interactive Circle of Fifths
(I have no affiliation with this site, btw)
In case this link doesn't work, here's the order of notes around the circle.
C-F-Bb-Eb-Ab-Db-F#-B-E-A-D-G (going counter-clockwise in forths...this is the order we'll be using...)
C-G-D-A-E-B-F#-Db-Ab-Eb-Bb-F (going clockwise in fifths)
Since this is written for the beginner guitarist/bassist, I'll briefly describe the COF. (It will help if you pull the above site, or any other up to refer to while you're reading.)
The COF organizes all 12 musical keys, starting with "C" at the top. If you progress around the circle clockwise, the notes (tonics) are a fifth apart. Progressing counter-clockwise, the notes are a forth apart.
By learning the circle, you'll also easily be able to tell what chords are common for a given key. In the link above, the example given is in the key of "C." You'll notice that immediately to the left and right of "C" are the IV and V chords (F and G).
So, if you know the circle, and your band leader says, "Let's jam a I-IV-V in "C," you'll know the chords are, "C" "F" and "G." Learning the COF gives you the ability to transpose easily to ANY key...just look to the left and right of the tonic, and voila!
OK...so how to use this to help you learn the fretboard. I'm a huge fan of combined excercises...and this is one of them. Staring at the COF is boring...so here's a way to combine theory with practice.
First of all, concentrate on frets 0-11 first. We'll come back to the higher registers.
Start on your lowest string...we'll assume most of you aren't playing 7 string guitars, or 5 string basses. For those that are, it's the exact same principle.
Try progressing first around the COF counter-clockwise, or in forths. Start at the top with "C." Find "C" on your low E string (8th fret). Play the note, while saying it aloud.
Then, go to the next note...counter-clockwise...and you'll be looking for "F" (1st fret).
Then, to Bb (6th fret), and so on, completing the circle to "C."
Once you've completed the circle on your low string, move up a string and repeat on all the strings. Try using a metronome set very slow and play whole notes. As you progress, try half notes...and up to 16th notes!
Once you've mastered frets 0-11, include frets 12-23 (or as many as you have) in the excercise. Once you're pretty comfortable with 4ths, try moving clockwise around the circle in 5ths.
You won't learn all the notes overnight...but you WILL learn them. Include this in your daily warm-up and let it slowly sink in. You'll not only be learning practical application, but also valuable applied theory.
Oh...and one other side benefit. I mentioned I really liked combined excercises, right? Well, another huge benefit in doing this excercise daily is that you're actually performing some ear training as well. You'll be teaching yourself what a forth interval (to begin with), as well as each note (tonic) sounds like.
Theory, ear training, and practical application...all in one! Hope this helps and let me know of any questions!