I haven't seen any info around about what actually causes people to get bounties placed on their head.

I suspected it was just from killing newbies in nation space but then I got one for killing a newb (in a consensual fight) in Sedina.

Does anyone have any links or info I could read on the subject?

Anything in monitored space.
that includes transports, NPC's, players.. you name it. is it liked, it generates a bounty....

....after a week.

1) you cant have a bounty on your head from a nation if you have a good standing with this nation.

2) kill [w/o die] around 10-20 players* or NPC* from a nation

* i am not sure about the numbers and if NPC work.