Lisp

The most popular lisps are Emacs Lisp, Clojure, Common Lisp, and Scheme.

Guides

Common Lisp

• Practical Common Lisp
• Common Lisp: A Gentle Introduction to Symbolic Computation
• On Lisp
  
  

Scheme

• Structure and Interpretation of Computer Programs
• How to Design Programs
  
• Teach Yourself Scheme in Fixnum Days
• An Introduction to Scheme and its Implementation (mirror)
• The Little Schemer

Also, scheme-style.

Implementation

"Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp." (Greenspun's tenth rule of programming)

• Scheme in Python
• Lisp in C
  
• Lisp in C++

Comparisons

• Common Lisp, Racket, Clojure, Emacs Lisp