These seem to be similar to the ser/estar? I don't understand them very well can someone enlighten me?
Por is used, among other uses like fixed expressions like: por favor (please), por Dios! (by God!), por aquí (around here), por avión (by plane), por qué/porque (why/because), when you want to say the reason why you do something: Trabajo por ti - I work for you.

Para is much easier, it shows the target of what you do: Trabajo para ganar dinero - I work to earn money. El regalo es para mi hermana - The present is for my sister.

I hope this helps.

Here is a link that I printed from Foro at least a year ago and refer to often.
Hope it's a help for you.