6,7,9ect

lets say i'm playing a C chord and i want to find the C6,C7,C9 ect is there a way to find it from the chord i'm playing if so how?

basicly you need to know the C ionian mode for this
the number with the chord, is the step from the scale you need to add:
the scale is:
C D E F G A B C
1 2 3 4 5 6 7 8
so basicly
C6 would be adding the 6 to the major triad
which is c e g
im not explaing that good i guess, but maybe others will be able to explain better, or i'll take my time to do it better later today
by the way can anyone explain what is inverted chords or whatever the term is are about

later
by the way as you noticed numbers are between 2 and 13
basicly after 7, notes repeat themselves only in higher octaves, so the difference between 6 and 13 would be the octave you add the note from

If you want to make a C6, just add an A note, the 6th tone from the C major scale, to a C major triad. A common fingering would be -

3
1
2
2
x
x

If you want to make a Cmaj7, add the 7th tone of the major scale, a B note, to a C triad. Fingering -

3
5
4
5
3
x

If you want to make a C7, add the 7th tone of the minor scale, a Bb note. Fingering -

3
5
3
5
3
x

9ths are a bit of an enigma. They're built on the dorian scale, I believe. Add the 2nd and 7th notes of the C minor scale to your triad. Like this -

3
3
3
2
3
x

Here's a pretty cool page for chord reference. It's not a lot, but its got the basics. It's also a good source of inspiration. When I run out of ideas, I usually look through chord books and play the oddest chords in there. Sometimes it gives me some good ideas.

http://www.1christian.net/guitar/chords.html