Next time, please tell us at least what exact version of the application you have. The illustrations in my previous post many not match what you have.
This is the Photoshop forum. I stress this just in case you have Adobe Photoshop Elements, which is NOT Photoshop; there is a separate, dedicate Adobe Photoshop Elements forum at:
http://forums.adobe.com/community/photoshop_elements?view=discussions
(It seems odd that you'd start out with the very expensive full version of Photoshop and not be familiar with its absolute basics.)
Please read this FAQ for advice on how to ask your questions correctly for quicker and better answers:
http://forums.adobe.com/thread/419981?tstart=0
Thanks!