"On Lisp" is a good book but perhaps too advanced for an introduction, whereas his "ANSI Common Lisp"[0] is better suited to the purpose. Barski's "Land of Lisp" has also received positive feedback.[1]

I'd be interested to see what others consider a suitable general learning path for Lisp.

[0] http://www.paulgraham.com/acl.html

[1] http://shop.oreilly.com/product/9781593272814.do

http://shop.oreilly.com/product/9781593272814.do

Though it is an alien...

Btw., for a decade or so O'Reilly actively refused to publish Lisp books - which did not make them very liked in the community.