i say that fretboard logic is worth it, especially if you dont have a good teacher (or you are selfeducated). Theres plenty of resources on the web, but i have come to appreciate the effort bill edwards has put into his series. Its a logical step by step thing where each section builds off the last, its worth every penny, its pretty much my private guitar tutor (plus you guys and jdarks) even after having all three editions for 7 years, i still refer to them daily.
To add on to everyones answers, the important thing with the 5 chord forms is to learn them as open, then as barre forms (same fingering, but using fingers 2 3 and 4 for the shapes and the 1 finger to barre the "open" notes, and then move them up and down the fretboard, so that if you play an E form, barred first fret, it becomes F, and an A form barred second fret, becomes a B chord.
Okay once you learn this, then heres the secret.
Play an open C form. Now at the end of the form (the fret where the root lies) play your A form.. Now you are playing the same chord, but different position. Now where the A form ends, play your G form, and you are STILL playing a C chord. Continue thru this process and you will see that from fret 0 - 12 the C A G E and D forms lined up back to back will show you 5 ways to play the same chord up and down the neck.
Next you learn what degrees each note in each form are, and where your 1,3,5 nuclei are.
Then you will start to see how all the chords, scales, triads arpeggios and whatnot lay over eachother and connect to eachother, to give you a roadmap for the fretboard no matter where you are.
Anyways I do reccomend the books, its a small investment (get the SE I and II combined, its not that expensive). there are countless ways and people to learn music from, but hey ive been locked up in this room with a guitar, my fretboard logic books, google and a shitload of hendrix,GD, zeppelin etc. Thats how i learned and id never take it back
and if you have any problems working through the material feel free to contact me ive practically memorized the books