Lisp Intro by Len Schubert
Lisp tutorial by Gene Kim
There are many other Lisp introductions online, e.g., see Philip Fong's (FU) 4-part Lisp tutorial. But don't take too much time looking at the options -- take a hands-on approach using one of the suggested primers, working directly under alisp on the UG network.
Some good Common Lisp texts and further tutorials include Wilensky, Common LISPcraft (Norton); or Peter Seibel, Practical COMMON LISP, Apress, 2005. These are excellent texts for learning Lisp. But see also the very good text by Peter Norvig, Paradigms of Artificial Intelligence Programming; the Indiana University Lisp Primer; the collaboratively developed Common Lisp Cookbook; and "Cliki", the Common Lisp Tutorial Wiki for some additional useful quick introductions.