Don't start with Kant? Even the original German is supposedly incomprehensible.
It is the arbitrary point where I've decided to stop falling backwards through a trail of connected works, though. I got here because it seemed reasonable to backtrack to Hegel & Adam Smith from Marx, and then from there I figured Hegel was closely enough related to Kant to step back again. I figure if I can't make sense of it, I'm only out time.
Really, though, what I'm interested in is how people are organizing their learning. :)
That's a subject I've always found fascinating, probably because I'm so bad at doing it myself.