The first thing you need to do is research as much as possible about what it takes to start up a business in your state. There are scads of resources you can use -- including lawyers.com.
Other sources would include the official state web site, where there will no doubt be lots of information about starting up your own business. You should also check with the city where you plan to do business. This research would probably answer most of your questions insofar as the licenses you may require.
You should also learn about your tax reporting requirements, which can be detailed and onerous for new business owners.
A next step would be to square away the ownership arrangement between you and your partner. For example, are you going to be 50/50 owners? Who is going to contribute what? Are you going to incorporate or form an LLC?
You should also look at issues that may arise from operating out of your home. Will your insurance cover you? Would you violate any local zoning rules or other ordinances? Whose home are you going to use?
Next, you also need to write out a business plan. Figure out a budget and how much money you will need. Where will you get it? How are you going to get customers?
You should also hire a lawyer and an accountant to help you through the process. You should get to know a banker, as well. In short, start developing relationships with people who will be good and necessary resources for your business.
While this list is not exhaustive, it does help to underscore that a lot of pre-planning is involved before starting up a new business.
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