The one book I recommend to anyone contemplating starting their own business is The Beermat Entrepreneur by my friend, and ex-rock star Mike Southon (aka Mike Fab-Gere).

Disclaimer: not only was Mike and his band the band at our wedding, but I have also invested in his latest venture, so I am definitely partial, but that book is one of the "wish I had read that before..." books, and an entertaining read as well.