Consulting is an activity some librarians are occasionally asked to perform as an outgrowth of their profession, while others may be considering it as a part-time or postretirement career. This article is a primer for the librarian who is interested in being a consultant. The author, who has performed numerous library consultations in her career, discusses the attitudes and skills that make a successful consultant, together with suggestions for finding clients, setting rates, writing a proposal, negotiating a contract, performing the actual consultation, and writing the final report. Consulting ethics are reviewed, and sources of further information are included.