Playing basic kid songs on guitar is easy if you follow these simple steps and practice a little bit regularly.

If you don't play guitar at all but want to, here are some scratch beginner lessons to get you started. Each of these video lesson is about 60 seconds long and will have you playing right away. After you understand these simple basics you can learn as many new chords, rhythms and songs as you wish.

#1 Guitar anatomy (link here) Learn the names of the parts of the guitar.
#2 Holding the guitar (link here) Learn how to properly hold the guitar for lefties and righties
#3 Tuning the guitar (link here) Learn to tune the guitar to standard tunings
#4 Strumming the guitar (link here) Learn basic strumming technique
#5 The left hand (link here) Learn the string, fret and finger numbers to make chords
#6 First chord "D" (link here) The first chord to learn is a "D" chord
#7 Making good notes (link here) Troubleshooting left hand problems to make good notes and chords.
#8 Strumming chords in rhythm (link here) Nice even strums for your chords
#9 Second chord "A" (link here) Your second chord is an "A" chord
#10 Change from "D" to "A" chord (link here) Learn to change from a "D" to an "A" chord and back again.
Once you can do these you are playing guitar. Now you can add as many new chords and rhythms as you like for the rest of your life. Here are three more ideas to keep you moving forward. 
#11 Sing while playing (link here)
#12 How to use a guitar capo (link here)
#13 Perfect rhythm lesson (link here) A sure fire way to tap into your perfect natural rhythm. I demonstrate with a mandolin but the theory works for guitar and uke as well.

Learning the Ukulele is easy as 1-2-3

Ukulele is a perfect instrument for small hands and people that just want to have fun playing music. Learn a one finger chord, a two finger chord and a three finger chord and you can play tons of songs. It's actually hard to make bad sounds on a uke. Pull out a uke and people smile.

I'm not much of a uke player but I can get you playing simple songs instantly. For real, you can learn simple songs in just a few minutes. With three chords you will be able to play many of the popular kid songs you know.