The Board of Immigration Appeals (BIA) is part of the Executive Office for Immigration Review (EOIR), a division of the U.S. Department of Justice. The BIA handles appeals by immigrants or the U.S. Citizenship and Immigration Service or USCIS (formerly the INS) from decisions of individual immigration judges.
Published Decisions: The Board issues "Interim Decisions" (I.D.). Selected decisions of precedential value are published in Administrative Decisions under Immigration & Nationality Laws. Administrative Decisions are posted back to Volume 8 (1955) in the EOIR Virtual Law Library. In addition, published decisions are searchable from 1940 on Lexis (IMMIG;BIA) and Westlaw (FIM-BIA), and from 1996 on Versuslaw.
If you want to see how a BIA decision has been treated by subsequent decisions and the courts, you can Shepardize the citation on Lexis, or run the citation through KeyCite on Westlaw.
Unpublished Decisions: "Non-precedential" BIA decisions back to 1985 are searchable on Lexis (IMMIG;BIAAAU). A few significant but non-precedential "Indexed Decisions" are posted in the EOIR Virtual Law Library. Selected unpublished opinions are included in Westlaw's BIA decision database (FIM-BIA). Selected unpublished opinions are included in Westlaw's BIA decision database (FIM-BIA).
Procedure: BIA practice and procedure is explained in the BIA Practice Manual.