How to identify sensors, boards etc.

As I am sure you can tell I am very new to Audrino, I bought a beginner kit which was the most complete kit I could find. The problem I am having is identifying what is what. For example I am trying to find the temp sensor so I googled it found something that looked very close but am unsure if it is it, the numbers are 137 OH 12. Before posting I tried to find a reference, used google, etc. I want to go through this kit piece by piece use and understand each thing.

post a picture of the component.. That numbers isn't good for ID

Can you give a link to the beginners kit ? Where did you buy it ?
Perhaps there is a picture of all the components.

Have to tried the 'Blink' example sketch ? That is the first thing to try. The example is in the menu.
It should blink a led on the Arduino board.