All amateur radio operators must be licensed by the Country in which they reside, and U.S. amateur radio operators are licensed by the Federal Communications Commission (FCC). There are currently three levels of amateur radio license.
Technican Class License (Entry Level)
Technician Class licensees have access to a limited amount of the amateur radio spectrum, but included are the entire VHF and UHF bands, with some privileges in other bands. The test for Technician Class mostly involves FCC rules affecting operating practice, bands, and safety. Little technical knowledge is required.
General Class License (Middle Level)
General Class Licensees enjoy use of most of the amateur radio spectrum, with a few limitations. The test for General Class includes more technical aspects of radio, propagation causes, and some electrical theory.
Extra Class License (Top Level)
Extra Class Licensees enjoy use of the entire amateur radio spectrum and communications modes. Candidates for the Extra Class have to know more electrical and electronic theory, be able to calculate answers to technical questions and be well-grounded in propagation, band limits, and related topics.
The Fond du Lac Amateur Radio Club conducts Exams and Training classes.
Amateur radio license training manuals are available from ARRL, Amateur Electronic Supply (AES) in Milwaukee, and Amazon.com.
Another source of amateur radio training materials is the W5YI Group, which features Gordon West training manuals and related materials.
When you are studying for an exam, it helps to practice. Here are sources of practice exams: