My son is 6yrs old and has started learning the piano at school. He is only doing basic fingering exercises (no chords or anything yet). His grandfather bought him an electronic keyboard to learn on at home. My wife learnt organ when she was a girl. She still had her old organ books. So I thought with a keyboard and some books laying around I would just tinker around and see what I could teach myself. However, the chords shown in the organ books seems to be different from what I am seeing in the book that came with the keyboard and indeed is different from the chord tool on this website.

The organ books are showing the fingering for C chord as follows:
G| | |C| |E

While I am seeing this elsewhere:
C| |E| |G

Similar in the organ manuals, F is:
A| |C| | |F

instead of:

F| |A| |C

Why the difference? I don`t want to continue learning the organ chords if they are the wrong fingering.

What you`re being confused with is the inversion of chords. Every three note chord has a root and 2 inversions as follows (for C major)

C E G
E G C
G C E

you take the bottom note and put it on the top. The fingering for each inversion is different. For most size hands the most comfortable fingering is

C E G
1 3 5

E G C
1 2 5

G C E
1 3 5

1=THUMB
2=INDEX
etc...

write back if there is any confusion

So which one is `correct` to play? Both books are referring to the chord as C major. But
G| | |C| |E

and

C| |E| |G

make two different sounds so they can`t both be C Major.

G C E: C major in 2nd inversion
C E G: C major in root position
E G C: C major in 1st inversion

They are all C major. They all use the notes that builds thirds on the C major scale. The only difference is the order of the notes.

One learns about this in the rudiments of music.

you need not feel confused because C,E,G OR E,C,G OR GEC ALL ARE SAME .BYE ABINOAM RONG

I would refer to those inversions as C, C/E, C/G... is this not international standard?

There are some keyboards (e.g. Yamaha) upon which the auto (Single Finger) Chords will produce the correct sound (for the harmony) no matter what inversion you play the chord in. Is this where you are getting confused?

both versions of chord inversions are acceptable.

For dominant chords one writes: V7, v65, v43 and v42.