Light Metering - help!

I posted a question on the DPS forum regarding light metering. I'm not fully understanding how it works yet. I've read my manual and also some articles from Ken Rockwell's sight and I'm still not totally grasping it when I try to apply it to taking shots. I will be checking out an exposure & lighting book from the library tomorrow so I'm hoping that will help. But in the meantime, this gave me something to post about on my blog. :D

The shots above were taken around 5pm today. The lighting was exactly the same for both shots. What's interesting is when I took the shot from directly above one of the lit candles, the background was completely black. But yet, the top photo shows more lighting! I know it has to do with the light metering, so I just need to understand better how it works and how it affects my shots. :)

Btw, these shots are mostly SOOC (straight out of camera) -- except for doing a quick defog to reduce the digital haze (that is in most photos).