I am interested in starting a business.. I need to know what are the things that I have to have by law before I do any work... can you help..

For to vague of question, there it would take 1000 pages just to cover IRS rules on starting a business,

Another 10000 about business plans, business loans , business insurance, city, county and state licences. Bonding if your businss requires that.

Depending on business have you done a marketing plan, for a location have you done a traffic survey

I could go on and on and on.

What type of business, what county, if US what state will help narrow some things.

Are you going to start a business transporting atomic waste from power plants, or a dog walking service , laws will vary

As Chuck noted your question is really too vague to answer. The type of business has a huge bearing on what needs to be done.

I can point you to two excellent resources to help you:

www.score.org an association of retried execs who volunteer their expertise
www.sba.gov the US govt's Small Business Administration site

You can also search the WEB for Business Plan software, that can walk you through the process of developing a business plan.