Sure, for typesetting:
Grab the text tool (Shortcut-key T)
Click and Drag with the mouse to create a box (Draw the box over the speech bubble)
Copy from the Script (Usually a text file, or a post on a forum)
Paste into the text box.
Align center (Look on the top bar, it should be up there somewhere)
Change the font(on the font bar up top, or where ever it is in your version)
Change the size (Same area as the font bar)
And position the text box to center the text.
For a more in-depth introduction to typesetting:
http://senbonzakura.kageyoshi.net/2009/05/02/typesetting/Using photoshop is just like riding a bike, you never really forget how to use it, but the bike kept upgrading and getting shiny new features while you were away.
Let me know if you want the test.
Also, on another note; We're ALWAYS recruiting staff!