What type of lincensing do I need to start a home improvement company?

I want to start a home improvement company

in the state of Maryland

You need an EIFN number so you can setup an LLC or some sort of corporation (See: http://www.maryland.gov/portal/server.pt?open=18&objID=419626&mode=2&cached=true ). You also need a Sales and Use tax certificate. The license info you need can be found here: http://www.dllr.state.md.us/license/occprof/homeim.html for home improvement.