Nuclear radiation/meltdown risk

I spoke about this on another thread. I am frustrated about the lack of clear, consistent information about the potential risk of radiation, either from the existing 'venting' or what would be possible in the event of a proper meltdown. Briefly:
- what information is coming out about the level of radiation so far released from the Fukushima plants as a result of the 'venting' of gases and the explosions occuring at the reactor?
-Where are radiation recordings being experienced?
- What are safe levels for humans?
- if there was a meltdown, how far widespread would potential radiation poisoning risk be?

Not trying to be alarmist, but I believed people should be as fully informed as possible. The constant contradictions, flip-flopping and sleights of hand from the Japanese Government (e.g. change units of measurement for radiation levels) is concerning and seems to be more about keeping the populace confused, while they scramble to defuse the situation.

there's been a lot of talk in the other threads about what's going on in Tokyo in regards to the nuclear stuff. Here's some links to check out what's behind the big scary articles and random people saying it's the end of Japan :

This one is in layman's terms with good headings to tell what's going on:

http://www.bbc.co.uk/news/world-asia-pacific-12732015

Deeper in Detail, I linked to page 3 with summary...
http://www.theregister.co.uk/2011/03/14/fukushiima_analysis/page3.html

Also here is the IAEA:
http://www.iaea.org/newscenter/news/tsunamiupdate01.html

They all talk about what terms mean and what is actually happening, as well as how much radiation, what type, and what's showing up in people vs. what gets released/decayed before it reaches people,