[Skarlath]

I was on the verge of caving and asking if there was such a button over here. But then I found it! MySV->Quick Links->Mark forums read.

Phew!

I had posts from months ago showing up on "recent new posts" I guess by posting this i'm just showing up my forum newbishness, but at least I am doing so after being able to sort things out!

[Darydale]

I had no idea. Thanks for being a noob so we don't have to.

[Nubb]

Bottom of the main Forum's listing is a Mark All Forums Read link.

When in a forum, the Forum Tools dropdown has a Mark Forum Read option. :)

(noob!)

Edit:
Forum Tools. Not Thread Tools, which I originally posted. :)

[JAdams]

Most useful; thanks for the tip!