This booklet provides information about the basic principles of portfolio development, outlining three types of portfolios and offering examples and reflections. The three types of portfolios are process, product, and showcase. Each is compiled for a different reason, though they all: have a specific purpose, are developed for a specific audience, contain work samples, and include reflections. The purpose of the portfolio determines how it is organized. All portfolios should include a table of contents, title page, and introductory section. Clip art and other graphics are optional. Written reflections are essential. Teaching reflections consist of description, analysis, and planning. Teachers must consider four areas before writing a reflection: audience, clear writing, voice, and bias. Many states are adopting new methods for granting beginning teachers' licenses. One popular method is the creation of a product portfolio with specific activities correlating with the Interstate New Teacher Assessment and Support Consortium (INTASC) standards. The booklet describes the INTASC standards and discusses how to use an INTASC portfolio. Finally, it describes the use of teaching portfolios for evaluating inservice teachers, suggesting how teachers can organize them, and discusses showcase teaching portfolios constructed by teachers competing for awards. (Contains of 18 resources.) (SM)