I'm glad you found it, so don't leave until you tell us where it's located!
Excellent idea!!
Go to "Profile"
And then, the reason I didn't see it, just above the orange bar are 3 horizontal buttons. The middle one is "Modify Profile" and when you put your cursor over it, the pull down shows 6 options, with the 4th one being "Notifications". Click on that.
And the second box was the animal I needed. Clicking that activates the action where any topic you start or reply to, you'll now get an email to tell you.. The third button is where you set how often you want that notification. I'm an Instant guy, because I consider forums like a conversation and I don't want to ignore anyone.
And, even if I'm unable to reply right away, the email is sitting there to remind me there's been a reply and I have an instant link to go right back to where I was in the topic.
And the little yellow "I like bacon" guy is what I use on all forums because he's easy to pick out, marking where I last replied, so I know where to start reading..
Oh, and I do like bacon.