Great idea! I loved your Conversations From The Pale Blue Dot.
On the topic on free will there is Dennett's Freedom evolves, what I liked about it is that his starting point is more of "When do we consider ourselves responsible?" or as he himself put it "The varieties of free will worth wanting" rather than "Do free will exist?".
The Science Network has lots of good stuff on these subject for example a very thorough lecture with Patricia Churchland on free will, a debate on Can science tell us right from wrong?.
I know that Owen Flanagan has written extensively about eudamonia e.i. human flourishing and offer quite a lot of material for free on his website.
I'm about to launch a new website (as a personal project; it's got nothing to do with SI or CFAR) about naturalistic views of the world, and that website will contain links to engaging and accessible books and articles about naturalistic approaches to:
What links do other LWers recommend on these topics? To show you what kinds of articles I have in mind, here's what I have so far:
Seeking Truth:
The Self & Free Will:
Ethics and Society:
Happiness and Self-Help:
Meaning and Spirituality: