recommend a book/resource for learning about.....

[UncleSalty]

I'd like to learn more about basic political theory, particularly in the US but World politics interests me too.

Are there any basic primers or websites that discuss foundational issues such as the left/right spectrum, conservative vs. liberal, the origin of our existing political parties and their original platforms vs. today, etc...? (Ideally something non-biased if that's even possible.)

Basically when I try to have an intelligent discussion about politics I feel extremely undereducated and I'd like to know a little more what I'm talking about.