Reading code on paper is always more difficult than reading code on screen - perhaps use a set of multi-color highlighters?
I'm not sure if experienced LISP users can read LISP well on paper, my guess is that they'll also "Lost In Stupid Parentheses" if they have to read from paper.
Paul Graham's book is definitely a good start and a good read (surprisingly a programming book can be a good read in case of his) for the style of Lisp.
He's also a good thinker and active person in the CA startup scene in recent years.
Scheme is also a clever alternative approach with the MIT textbook, but it definitely has more syntactic sugar than Common-lisp so you need to be aware of those when you jump over to another dialect.
Those who start in LISP think quite differently from those who start in C/C++ or FORTRAN, e.g. solving problems by recursion in common in LISP.