Taking a Screenshot?

I cant for the life of me figure out how to take a screenshot on my macbook.

i found something online that said command shift3 but that didnt work.

and after i d it what do i do?

im used to just hitting print screen on my pc.

thanks!

:::edited:::

nevermind. it did take the screen shots...but my computer was acting funny and didnt show them on the desktop like they should....and now they are there. my computer is moody.