I say if he wants to start at 7, let him do so. Just make sure that you get a good teacher (easier said than done, I know) that makes it more about having fun than learning the guitar.
With my eleventh (?) pick, I'll take a little Willie and Waylon!
Mama, Don't Let Your Babies Grow Up To Be Cowboys
Verse 1:
D G
Cowboys ain't easy to love and they're harder to hold
A D
They'd rather give you a song than diamonds or gold
G
Lonestar belt buckles and old faded Levi's and each night begins a new day
A
If you don't understand him and he don't die young
D
He'll probably just ride away
Chorus:
D G
Mamas don't let your babies grow up to be cowboys
A
Don't let them pick guitars and drive them old trucks
D
Make them be doctors and lawyers and such
G
Mamas don't let your babies grow up to be cowboys
A
They'll never stay home and they're always alone
D
Even with someone they love
Verse 2A tone higher)
E A
Cowboys like smokey ol' pool rooms and clear mountain mornings
B E
Little warm puppies and children and girls of the night
Them that don't know him won't like him
A
And them that do sometimes won't know how to take him
B
He ain't wrong, he's just different but his pride won't let him
E
Do the things that make you think he's right
Chorus
E A
Mamas don't let your babies grow up to be cowboys
B
Don't let them pick guitars and drive them old trucks
E
Make them be doctors and lawyers and such
A
Mamas don't let your babies grow up to be cowboys
B
They'll never stay home and they're always alone
E
Even with someone they love
__________________
Let's get drunk and do philosophy.
If you took a burger off the grill and slapped it on your face, I'm pretty sure it would burn you. - kermitology
For anybody that wants to learn how to fingerpick, The News by Jack Johnson is an excellent song for starting. (I've been teaching some of my kidlets it recently) http://www.guitaretab.com/j/jack-johnson/25921.html
Here's a rarely heard (and rarely tabbed!) Blue Rodeo song, Angels (not Dark Angel). It's the last track on Lost Together, and its good for beginning guitarists with a nice variety of open chords.
The G/B chord suggested below, I usually just play as an open C and I think it sounds just fine.
"Angels" by Blue Rodeo
Written by Greg Keelor and Jim Cuddy
From the album "Lost Together"
WEA Records 1992
Transcribed by Kevin Ross (kjross@yahoo.com)
Visit my web site at http://guitarcafe.homestead.com/
Note: There's a chord in the bridge that is a little
strange. I play it as x2x003 and I'll write it as G/B here.
Intro: E E D A E G E G (x3)
E D A E G E G
Sometimes it all looks like some Chagall
E D A E G E G
I close my eyes and disappear for awhile
G/B A
And the world is falling
G/B A
Slowly out of view
G D A E G D A
While the angels are singing, they are
G D A E
Yea the angels are singing
G D A GGG
home
3 o'clock in the morning
And I'm feeling no pain
From way up here
It sure all looks the same
And the stars are spinning
Like pinwheels in the sky
CHORUS
PIANO SOLO ON G/B A (x4)
END OF PIANO SOLO ON CHORUS
GUITAR SOLO ON CHORUS
I think I'll stay here a little longer
Close my eyes and go back to nowhere
And I wonder if I'll ever
Get used to this life I've been living
While the angels are singing
Singing me home
Yea the angels are singing
G D A G
Home
A G
Home
A G G
Home
[G]Sitting in the morning [B7]sun;
I'll be [C]sitting when the evening [A]comes.
[G]Watching the ships roll [B7]in
And I [C]watch 'em roll away a[A]gain, yeah.
[G]Sitting on the dock of the [Em]bay
Watching the [G]tide roll aw[Em]ay.
I'm just [G]sitting on the dock of the [A]bay
Wasting [G]time. [E]
I left my home in Georgia
Headed for the 'Frisco bay
'Cause I had nothin to live for
And look like nothing's gonna come my way
So I'm just...
[G]Look [D7]like nothing's gonna change [G]
E[D7]verything [C]still remains the same [G]
I [D7]can't do what people tell [G]me to do. [F]
So I guess I'll remain[D] the same.
Sittin here resting my bones
And this loneliness won't leave me alone
It's two thousand miles I roamed
Just to make this dock my home
Now, I'm just...
A tone higher) 
