I find the easiest way to curve text is to create a cirle or eclipse with the shape tool (remebering to set background colour to transparent, and foreground to whatever your canvas is), then select the text tool and position it over the shape where you want the text to be. Look for the cursor shape change to denote curved text before you click.
Once you apply your text, you can rotate it to get your fine positioning.
There is probably and easier way to do this, but its worked well for me to now!