Accreditation is important because it signifies that the doctoral program and the school that offers it have met nationally recognized quality standards. The staff are qualified, the program includes the necessary, important information, and the degree you receive will be recognized by your field and by your peers. Public universities and colleges are all accredited, as are most private universities and colleges. With the advent of online programs, it's more important to verify that your degree will be granted by an accredited organization so that you don't spend all your time and money on what will end up being a worthless piece of paper once you hit the job market.
Before you apply to a doctorate program you should find out whether or not the school and the program are accredited by a nationally recognized accrediting agency. To find out this information, look at the school's website under the "About Us" tab. Most schools will list accrediting information online, but, if not, inquire with the doctoral program directly about accreditation.
CHEA maintains a database of institutions and programs that are accredited by United States accrediting agencies. If an accrediting agency is recognized by CHEA, it has met six standards. The accrediting agency must show that they require advances in academic quality, accountability, encourage self-review and improvement, use fair decision-making, regularly review their own accrediting practices and have sufficient resources to continue operating.
Schools may seek accreditation from various accrediting bodies. However, in order to participate in federal funding programs or for students to receive federal financial aid, the program must be accredited by a body that is recognized by the United States Department of Education (USDOE). The CHEA has more rigorous standards for recognizing an accreditor, but if the USDOE does not recognize the program's accreditor, you will not be able to apply for federal financial aid to assist you with school expenses. See the References Section for a link to a chart giving you information on different accreditors and whether they are recognized by the USDOE, CHEA or both.