Below is the my personal "ultimate reading list". All of them sit on my bookshelf either electronically or physically and are well worth the read.
These books are mainly concerned with software development at a conceptual level. However, there are a few hardcore technical books in there too. Basically these books got me where I am today, hopefully you'll find them useful too.
I'll add to this as I think of more, but this is a good start.
And here are a few links to some free online books...