Chord: A group of notes sounded together in harmony. It's as simple as that. Every chord relates to a scale in some way. Learning how to construct scales is important. I wont write a huge post explaining it, as Guitartricks has whole sections on the various scales and sound clips for them. Have a look round....I would advise you start with the basic major scales: Begin with E and work you way up the Fretboard. Once you can play one major scale on the guitar you can play any other by thinking in frets. After the major scales, go for the Minors (harmonic to start with - its easier.) The pentatonic is also a good scale to learn as its very widely used. Once you know the sound of it you will definitely regognise it in the music you listen to....I know Petrucci uses it.
Be warned, there are many different ways to play the same scale! Steve Vai advises you learn five ways of playing every scale you know up and down the fretboard. This takes time and practice.
Once you know how to constuct your scales, chords will make more sense to you. Simple chords work in triads. For example the first (or 'tonic') triad of E major is E G-sharp B. Thats a major triad. To get E minor's triad, flatten the third (ie: G sharp becomes G.) You can later make diminished chords, augmented chords and add extra notes to them....the possibilites are endless.
Once you learn the notes and shapes of chords start creating patterns with them and see what you like. If you want a starting point, pick a song you like and locate a 'tab' for it on the web, or perhaps even just a simple list of the chords it uses. I started with Oasis' Don't look back in anger on my very first guitar lesson:
C, G, a minor, E, F, G, C for the main verse. Thats using the 'open' chords as theyre at the bottom of the fretboard using some of the open strings.....nice way to break into the world of guitar playing.
After chords you can learn how to solo your scales on top of them.
If you find youself getting hopelessly stuck and frustrated dont pannic....it happens to all of us, even the most experienced professionals. You might consider getting yourself a music teacher so all this stuff can be explained properly and at a pace that lets you take it in, because lets face it, its a hell of a lot to learn.
Good luck, Chacron.
'There's no such thing as bad weather, there's only the wrong clothes...'