If you only want to read one book about entrepreneurship, my personal view is that “The Art of the Start: The Time-Tested, Battle-Hardened Guide for Anyone Starting Anything” written by Guy Kawasaki is the ONE.
You can read most part online from Google Book at http://books.google.com/books?id=-gXlwJnnNoEC&lpg=PP1&dq=label%3A%22entrepreneurship%22&pg=PP1#v=onepage&q=&f=false
By the way, Guy Kawasaki’s blog “How to Change the World” is also a great resource for aspiring entrepreneur.