The most pleasant way I have found of accessing the Common Lisp standard is through Info. Build and install the Info files as described on http://www.phys.au.dk/~harder/dpans.html. Then add the following to your ~/.emacs.el:
(require 'info-look)
(info-lookup-add-help
:mode 'lisp-mode
:regexp "[^][()'\" \t\n]+"
:ignore-case t
:doc-spec '(("(ansicl)Symbol Index" nil nil nil)))
You can look up the symbol at point with C-h S.
