Uh, PS already has tools to do that so just use them. Click on the Type tool, it should be in the box with all of your other tools like eraser, pencil, etc. and it looks like a T. Now click on the document window and type your text and click the check mark at the top of the screen. Now if you look to the left of the check mark you will see a T with a curved line under it...those are the basic text warp tools.
The fancier way to make curved text is text on a path. Use the pen tool and make whatever path you like and as curvy as you like (even a circle). Now click on the type tool. When you click on the document window to start typing your text, click on the path and your text will follow the path.