I am not familiar with Emacs, but I still tried to install Emacs as well as SLIME for trial.
Here are simple steps for setting all these up:
$ sudo apt-get install clisp emacs slime sbcl cl-asdf
Then, in the .emacs file:
(setq inferior-lisp-program "/usr/bin/sbcl")
(add-to-list 'load-path "/usr/share/common-lisp/source/slime/")
Ref: How to set up Emacs + SLIME + SBCL under GNU/Linux