It'll depend a lot on your son's musical taste as to what he's likely to be inspired by, but try to find music that shows off the recorder both as a solo instrument and working with other instruments.
So some of the baroque sonatas by Handel or Telemann - which are also quite accessible to the intermediate player - would be a good starting point.
For something a bit more spectacular, Vivaldi's recorder concertos are impressive examples of what you can do with the instrument within its baroque domain, definitely for the advanced player but everyone can enjoy listening to them, and how well the recorder can work with other instruments.
For another example of working with other instruments, Boismortier's "4 Balets de Village" give you a couple of recorders in the French baroque style, alongside strings, baroque oboes and flutes, hurdy gurdies and French bagpipes, all together in a chaotic mess that somehow comes out sounding coherent, exuberant and magnificent.
There's just so much of this stuff if you know where to look.
Try the videos on charlottebarbourcondini.com - BBC Young Musician 2012 finalist, the first ever on recorder, she played Vivaldi's concerto in C minor in the final, and a variety of other pieces in the category final including Linde's Music for a Bird , which is one of the great 20th century pieces for solo recorder.
Also check out players like Pamela Thorby and Evelyn Nallen, and groups like Red Priest and the Amsterdam Loki Stardust Quartet.
Evelyn's also found in the group Respectable Groove, playing in a very jazzy way on a very baroque selection of instruments.
Of course, your son may not find any of this inspiring at all, but I hope this provides you with something to start with.
You can find a lot of good stuff just by trawling YouTube, too - if you're prepared to listen to a lot of hideous terribleness in the process, anyway.
I know you said 'child-friendly', but I'm not really sure what that means
so I just gave you my usual selection of recorder music, because I'm not sure there's any such thing really.
I play in a group with some people I've played with since they were 12, and we've been on hardcore baroque consort music all the way and they love it.
Of course, they were already dedicated recorder players when we started the group...
music.stackexchange.com/users/1479/Matthew Walton
At the risk of being declared off-topic, can I recommend that if your son shows a modicum of talent, buy him an Alto recorder - preferably a wooden one.
The difference in sound is incredible, and it opens a new world of music.
I took up recorder in my 40s, after a break of 30 years.
Now in my late 60s, I have no intention of retiring.
The recorder is a much underated instrument.
There is so much Renaissance and Baroque music out there (transpositions on Bach's Anna Magdelena notebook are very nice introduction).
Composers like Telemann, Veracini, Marcello and many others wrote excellent tuneful and challenging stuff for the recorder.
You can form a consort, and play recorder without needing to be at professional level.
You can start on descant, graduate to Alto, try a Tenor and learn to play Bass.
If you are rich you can buy a Great Bass and a Contra Bass.
Then start rounding out your menagerie with a set of Renaissance instruments (A=415) and French
Baroque(A=466)
Worlwide
there are regular recorder weeks, where you can recieve tuition, play with others
both in both small groups and a "recorder orchestra" - Gabrielli is a favorite for an orchestra.
I'd better sign off before the "off topic" police hit me...
music.stackexchange.com/users/10991/kiwiron
There are many songs.
You can get the suzuki books, they have different levels http://www.amazon.com/Suzuki-Recorder-School-Soprano-Volume/dp/0874875536/ref=sr_1_2?ie=UTF8&qid=1402425647&sr=8-2&keywords=recorder+suzuki here on level 1, there are like 30 songs (didn't count).
Most of them are familiar and fun, teaching students technique.
I haven't played recorder for a while, but in my applied guitar class I went through the Suzuki series, they're fantastic.
music.stackexchange.com/users/7027/Gᴇᴏᴍᴇᴛᴇʀ
The book Red Hot Recorder is very popular with colleagues of mine who teach recorder (and their pupils, of course!)
I must stress this is just one example book though - there are loads of others.
music.stackexchange.com/users/9198/Bob Broadley
Are you looking for something simple to play, that he can play along with, like this selection from Zelda: Or just something fun to listen to, like this Recorder Orchestra:
music.stackexchange.com/users/10637/Caleb Hines
This one is a real inspiration to small children!
For older kids, check out more from the same (now adult)
Lucy Horscht or the BBC Young Musician of the Year videos from 2012 (Charlotte Barbour Condini) and 2014 (Sophie Westbrooke) or the parallel BBC Jazz competition in 2016 finalist Tom Ridout.
Each of those three beat all the other woodwind players to reach the final and have videos on YouTube which young teens love to watch.
music.stackexchange.com/users/38188/AnnFB
My young five year old son is learning to play the recorder. I would like to let him listen to some music to inspire him . What child friendly music is there that features the recorder?
Recorder music to inspire a young learner
music.stackexchange.com
<recorder>
music.stackexchange.com/questions/20162
music.stackexchange.com/users/12075/Lembik
Some of the baroque sonatas by Handel or Telemann - which are also quite accessible to the intermediate player - would be a good starting point for a recorder player. For something a bit more spectacular, Vivaldi's recorder concertos are impressive examples of what you can do with the instrument within its baroque domain, definitely for the advanced player but everyone can enjoy listening to them, and how well the recorder can work with other instruments.   Some child-friendly recorder music that could word as inspiration could be a baroque sonata by Handel or one of Vivaldi's recorder concertos.
Some child-friendly recorder music that could word as inspiration could be a baroque sonata by Handel or one of Vivaldi's recorder concertos.