I saw there's an online chat tool on this site called Shoutbox but I can't find where to start typing! I looked and looked, there are no FAQs or any info on this site that I could find.

If I didn't have a PhD this might make me feel kind of dumb.

just write your text in the white field on the right sight above the dark shout-button and then press the button...

Can you give me a screenshot of what you mean? I don't see the dark button or the white field.
I'm using Chrome; maybe it prefers other browsers?

The buttons don't show up when you visit the homepage but haven't yet logged yourself in, maybe that could be the problem ?

I can see it now, I'm guessing new accounts have to be approved first.