Shit. I have something like this here somewhere...
Lettering in PS is easy, though totally shitty compared to illustrator. You need a level above your art for baloons, and then above that layers with the words. Place all your text first whereever you want it to be on the page.
Remember that for the text to fit in ovals, you should format it like a diamond. Shorter lines on top and bottom, longest line/s in the middle. Also remember you can break the dialog up, have two bubbles or more overlapping each other to create unique shapes to put your text in.
Once you're dine placing your text, time to make the bubbles. Using the oval select tool, draw a circle around your first piece of speech. Do this for any connected bubbles/ Then use the polygonal tool to draw connectors between bubbles if you need them, and pointers, holding shift the whole time. Basically, you're going to convert your whole selection to one shape, so anything that is connected by the same stroke should be selected.
Now, on your bubble layer, go to edit-fill and fill with white. Then go to your layer blending properties and give it a black stroke of whatever thickness looks good.
Move on to the next bubble/s and repeat.
I LOVE BLUD BLOOD! - Rob Liefeld