Education, Examination, and Experience.
1)Need to meet education requirements to be eligible for the CPA exam. See http://www.cpaexamrequirements.net.
2)Need to pass the CPA exam. See http://www.cpaexamrequirements.net.
3)Most states require an Ethics exam to be written.
4)As well, many states have experience requirements, which vary from state to state. Many states require that this experience to be in public accounting, although more and more states are accepting experience in the accounting area in general. In most states, this work experience is required to be certified by a licensed CPA, although some states also accept work experience certified by chartered accountants.
Also need to maintain CPA license by earning CPE credits. Typically, 40 CPE credits are required every year in order for a CPA to renew their license. CPE credit can be earned by going to seminars or workshops run by CPAs.