I know there are tens of thousands of books on entrepreneurship. Help me find the best ones :)
Everything you do (in life and as an entrepreneur) should start with an underlying passion. If you aren't pursuing the things you're most passionate about, you're doing it wrong (or just for the wrong reasons). IMHO.
So in that regard, I'd highly recommend reading Simon Sinek's "Start With Why". If you're not up to reading a book, just Google his TED talk as a start.