Here are some links to reference documents dealing with Autotools in general and Autoconf and Automake in particular.
This tutorial uses Autoconf 2.61 (November 2006) and Automake 1.10.1 (January 2008). Some of these documentations uses older versions. the syntaxes could have changed quite a bit. These old syntaxes usually still work and are used in old project. It is useful to know them but it is a bad idea to use them in a new project.