I need to know how I would go about legally changing the last names of my husband, two kids and myself to my maiden name.

Depends.

Where do you live?

Here in Canada, you would have to contact the Ministry of Government Services.

I live in the U.S. in Ohio.

This is from a law site in OH regarding name changes:

http://www.namechangelaw.com/states/ohio/ohio.htm


And here is a copy of the free legal form you need to fill in:
http://www.ilrg.com/forms/namechange-minor/us/oh

You can buy forms online to file

http://www.inamechange.com/category_842__page_1.html

Also many states ( sorry not up on yours) has paralegals that adverste all sort of legal work, name changes are one they do