A 1/2 or 3/4 size guitar is strongly recommended for children. You can go to Guitar Center, Sam Ash, 30th Street Guitars (great indie shop), or Ludlow Guitars in NYC and the sales reps can help you and your child try them on for size.
If you're going to get an acoustic guitar, please know that nylon strings (on classical guitars) instead of steel strings (on contemporary guitars) don't hurt the fingers as much. Nylon string guitars are recommended for young children ages 4-6.
If you buy a guitar online, you miss out on the chance for the sales reps to give the guitar a complimentary tune-up, fresh strings, and double check the adjustments of the guitar.
Low Cost: LAUREN 30 INCH NYLON STRING STUDENT GUITAR $53
This ultra-affordable nylon-string guitar is easier on tiny fingers than the typical steel-string guitar. Many young students love this Lauren guitar - it's small, cheap, and stays in tune. Downside is that it does not have a guitar strap bolt.
Mid-Range: HOHNER 3/4 SIZE STEEL STRING ACOUSTIC GUITAR, $80
Mid-Range: YAMAHA 1/2 SIZE NYLON STRING GUITAR, $119
Mid-Range: YAMAHA 3/4 SIZE STEEL STRING GUITAR, $160
Highest Quality: BABY TAYLOR ACOUSTIC STEEL STRING GUITAR, $299
I love this guitar. It's my personal favorite and I use it every day. Superior quality and sound, lightweight, and a bargain given the depth and tone of Taylor Guitars. Will last a lifetime.
SQUIER STRAT ELECTRIC GUITAR BUNDLE, $109
This beginners set comes complete with gig bag, instrument cable, strap, strings, and picks. This is one of the cheapest electric guitar options on the market and a great choice if you don't want to make a heavy financial investment.
SQUIER STRAT ELECTRIC GUITAR BUNDLE WITH AMP, $139
Same as above, includes a mini amp.
FENDER STANDARD STRATOCASTER, $499
Fender strats are a solid choice for kids who are committed to learning guitar. Great quality and long lasting; an excellent investment.
INTELLITOUCH MINI CLIP-ON TUNER, $22
This tuner is easy to use and colorful, flashing red when a string is out of tune and flashing green once it's in tune. Makes tuning fun!
BEATLES GUITAR PICKS, $6
Everyone loves The Beatles.
KALA SOPRANO UKULELE GIG BAG, $18
Lightweight ukulele case with lots of padding.
3/4 SIZE ACOUSTIC GUITAR CASE, $44
My favorite case for acoustic guitars. There are more affordable options out there but I haven't personally found one I'm happy with.
FENDER FRONTMAN ELECTRIC GUITAR AMP, $59.99
This small cube amp has a nice distortion option and a headphone jack for silent practicing (score!). One of the cheapest amps on the market and a good quality option.