The F.C.C. does not require on-air personnel to be licensed.
But, on-air DJs, hosts, etc. are required to follow F.C.C. rules and regulations for on-air conduct and may be required to take transmitter readings as deemed necessary by the station's Chief Engineer.
In addition, if you plan to set up an Internet radio station you need not worry, either. The F.C.C. does not regulate streaming audio or webcasts on the Internet.