Matroids

Coxeter Matroids - Alexandre Borovik's introductory notes, examples and research.
www.maths.manchester.ac.uk/~avb/M-title.html

Coxeter Matroids - Neil White's research papers (mainly PS).
www.math.ufl.edu/~white/cox.html

Matroid - Introductory article from MathWorld with links and references.
mathworld.wolfram.com/Matroid.html

Matroid Decomposition - Electronic library of mathematics monograph by Klaus Truemper.
www.emis.de/monographs/md/

Matroid Miscellany - References, sources and open problem, collected by Thomas Zaslavsky.
www.math.binghamton.edu/zaslav/Matroids/