Other sources of information about Macaulay2

Web site

http://www.math.uiuc.edu/Macaulay2/ -- the main Macaulay2 web site: citations, binary distributions

Computations in algebraic geometry with Macaulay 2, Algorithms and Computations in Mathematics, no. 8, edited by David Eisenbud, Daniel R. Grayson, Michael E. Stillman, and Bernd Sturmfels, Springer-Verlag, 2001, ISBN 3-540-42230-7.
Computational Algebraic Geometry, London Mathematical Society Student Texts (No. 58), by Hal Schenck, ISBN-13: 9780521536509, ISBN-10: 0521536502, 2003, 208 pages.