Trying to Start Small Business in NY

It seems you need a license to teach school (of course) and a license to be a handyman in NY. But you may not need a license specifically to teach handyman stuff. However, recognize that if you are teaching things like electrician work, you still might.

Ask at your local library or community center or Y. Any of those places might be a good place to advertise your services when you're ready to, so you may as well develop the relationship now.

You may also want to talk to your insurance agent or a lawyer before you continue. If you are teaching people how to run a circular saw or wire a lamp, either of those could result in injury if done improperly. Find out how to protect yourself if you get sued. Also talk to that lawyer about incorporating, probably as an LLC. That is, if you're ever sued, you want to try to keep your house.

In addition to what jespah has said, you'll need to obtain a tax ID (EIN) number.

Visit the IRS website for that.

Eek I had forgotten about that. Of course you're right.

The information is here

http://www.businessnameusa.com/Answers/how%20to%20get%20new%20york%20handyman%20license.aspx

After license, you can teach at any place where your skills as a teacher are accepted.

You can work by yourself as a teacher without handyman license, but you might check anyway the business ID.

As long as you know the correct interpretation of the codes, no problem.
About the techniques to perform a task, these can be your own, as long as these techniques work the same or better than the conventional ones.