In the municipality you're considering, some of the laws you need to look into are:
Is there a minimum square footage amount that designates a structure as a permanent home? Believe it or not, some places dictate the minimum size you may live in.
Can you legally park it on the property in question?
Can you park it on the property without a permanent dwelling being present there too?
If so, can you live in your home as a primary residence (four seasons)?
Do the local zoning laws permit accessory dwellings like your tiny house on a trailer? If so, are there minimum requirements for square footage?
Does the accessory dwelling need to be built on a permanent foundation?
If you are not entirely tied into existing sewage systems, you will need to know what the waste water (black and gray) laws are.
Not a law, but you will need to investigate how to have your home insured. Because of the nature of tiny houses, especially those on wheels, you may have some issue getting insurance. Insurance and finance companies have not caught up to the tiny house movement, yet.