There is a program called "Comic Life" but I've never used it (I'm a Photoshop kinda guy).
As for comic fonts, I highly recommend BlamBot (
http://www.blambot.com/), which offers heaps of free and paid fonts. The free ones are quite popular; I've seen them used on a lot of web comics.
There are some useful articles on the site as well.
As for word balloons, I recommend you learn to make your own instead of using pre-made ones - you have more design freedom that way.