Maxima Documentation
 Reference Manual ( PDF version)
 Xmaxima Reference Manual
 Maxima by Example by Edwin L. Woollett
 A 10 minute tutorial for solving Math problems with Maxima by Antonio Cangiano
 Introduction to Maxima by Richard Rand ( PDF version)
 The Computer Algebra Program Maxima by Boris Gaertner ( ) zipped version
 by Robert Dodier Minimal Maxima
 Micro introduction into Maxima at Harvard U
 Symbolic Mathematics Using Maxima by Paul Lutus
 Maxima user interface tips — a collection of tips for customizing and interacting with the Maxima user interface.
 Graphics with Maxima by Wilhelm Haager
Publications
Books and articles which mention Maxima or Macsyma.
 BibTeX format bibliography of papers on MACSYMA/VAXIMA before 1994.
 Dynamical systems by J. E. Villate, in Portuguese and some parts translated to Spanish and English. Book that uses Maxima to teach a course on ”Dynamical systems”.
 A. BenIsrael, R. Gilbert: ComputerSupported Calculus. Springer: Wien 2002. ISBN 3211829245.
 Robert S. Maier ”The 192 Solutions of the Heun Equation”. Mathematics of Computation, vol. 76 (2007), pp. 811843.
 Robert S. Maier ”On Rationally Parametrized Modular Equations”.
 Joel Moses. ”Macsyma: A Personal History”. Invited Presentation in Milestones in Computer Algebra, May 2008, Tobago.
 Mathematical
Modeling and Simulation by Kai Velten
Kai Velten: Mathematical Modeling and Simulation, WileyVCH, 2009.
http://books.google.com/books?id=Czp1N5UWpyEC
A book on modeling and simulation exclusively based on open source software. It includes many examples from such diverse fields as biology, ecology, economics, medicine, agricultural, chemical, electrical, mechanical, and process engineering. Requiring only little mathematical prerequisite in calculus and linear algebra, this lucidly written text is accessible to scientists, engineers, and students at the undergraduate level. The book addresses a broad range of models from elementary statistical models to ODE and PDE models. The reader is introduced into CAELinux, Calc, CodeSaturne, Maxima, R, and SalomeMeca.
Other documents

Some
Baseless Opinions About Maxima by Robert Dodier
A presentation from Sage Developer Days 1. 
The Maxima Book
This is a very incomplete and in some places out of date user oriented manual. It is a work in progress, but is provided here in the hope it might be useful.
Update: This new version isn't all that different, but it has been updated a bit with regards to plotting and a couple other minor changes. Emaxima and install docs have not been updated yet. Mathematical content is essentially unchanged. Pictures should be of slightly better quality.  MAXIMA:
Science and Engineering Applications by Gilberto
E. Urroz
A collection of lecture notes, showing the use of Maxima and WxMaxima in science and engineering problems.  Computer
Based Tools for Engineers by
Javed Alam
The different sessions provide the necessary theory and the solution using Maxima for problems encountered in Engineering computing.