The topic this week with the Thrive Project is ISO and the Rule of Thirds.
Becky from Farmgirl Paints gives a good explanation of ISO. She explains it like a dimmer light switch. If you have a lot of light or you are outside, you would have the dimmer down low. If you are in a darker room with less sunlight, you would turn the dimmer up. The higher the dimmer (ISO) the grainier the picture becomes. Low ISO=crisper pics.
With the Rule of Thirds, you are supposed to imagine a grid with 9 boxes. Put the subject on one of the crosshairs. Becky has graphics on her blog to explain.