Relationship of Chords / Scales

Just a revision :

The relationship between notes: 
The major scale is king. It goes like this :
root tone tone semitone tone tone tone semitone root

Numbered as :
1 2 3 4 5 6 7 1

kapeesh?

Being a guitarist you want to think of it as distance between the various numbers. Try not to. Focus on the note indices. Being a guitarist you can focus on the note numbers 1 2 3 4 5 6 7 instead of c d e f g a b.
Just remember the names on the first two strings though. Or have an idea of the note names on the first two strings and you are good to go.

Next.

Common chord progressions : 

1 major chord goes well with major 4 , major chord of 5 and minor chord of 6

Learn where these are if your one is on the 6th string (bar chord on 6th) or on the 5th string (bar chord on 5th). Covers about a 90% of the songs :)

If you start on 6th string:
4th = same chord moved to string 5,
5th = same chord move to string 5 two frets down
6th = minor chord three frets up on string 6

If you start on 5th string:
5th = same chord moved to string 6
4th = same chord moved to string 6 two frets up
6th = minor chord moved to string 6 two frets down

Details? Lookup Diatonic harmonies. And here is a very simple explanation:
http://www.youtube.com/watch?v=fXIEmMDwc7E


Soloing? 
A major scale in key x is equal to a minor scale in 6th of key of x.

For C sixth = A.
Therefore Cmaj = Aminor