Not a good idea...for many, many reasons.
It might be better to enroll him in a non-contact karate class or an Aikido class when he is a little older but not boxing, a full contact sport with a long and verifiable history of causing brain trauma.
No idea why the guy told ya' to kill yourself. I think it's great that you are interested in singing up your child to boxing. Teaches lots of stuff and it's a lot better than being on the streets getting in trouble, among other stuff like good health, self-esteem, etc...
Anyway, like the first guy said, most boxing gym's start training from 10+. Not many gyms train kids under that age. If you happen to find such a gym then you are in luck.
Your best option is to sign him to Martial Arts. Those places train kids as soon as they learn to walk(I'm serious). Martial Artists are firm believers that teaching a child an Art is an excellent way to start life. Responsibility, confidence, respect, friendship, trust... Martial Arts instructors are strict to these things.
Again, if you happen to find a boxing gym that teaches really young ones, then you are in great luck. If not, Martial Arts is a good option
Though there may be exceptions in unusual situations where some freak of a toddler just has God given talent the youngest I have ever heard of any child boxing where they even have any concept of how to fundamentally throw punches correctly e.g. using legs, hips and shoulder rotation is 5 years old. My child is 3 in september but even though I have been boxing since the 1980's I have to resist teaching him because he is just too young, you will not find any boxing gym or club that will even think of having any one under 5 even train.
I'm from the uk, but from my knowledge most boxing clubs only start training kids from the age of about 10. Why don't u enrol your son into some martial arts school of some sort
These days you can learn how to sing over the internet. Check out Aaron Anastasi's singing video lessons here: http://www.voicevideolessons.com The videos are very easy to follow and to my surprise extremely helpful even for advanced singers. For beginners I would have to say this is a gold mine. I was able to improve my singing, voice tone and range in just under two weeks and I am an advanced musician, been doing this for the last 13 years.
I live in New York City, I wanted to go to a singing teacher but that would have cost me over $1400 per month. Good thing with this internet, $1400 it's a lot of money for me.
I have a toddler who enjoys wrestling, boxing and being rough. I think if I have him trained he will learn how to control being so crazy. I think he will learn a lot of discipline. I live in the Phoenix area, does anyone know of any gyms I can take my son to?