Do you have open on start up? I have 34, all bar my gmail are webcomics.
None, it's only set to open on one tab, google. Also, I don't use speed-dial, either. That seems easier on chrome for some reason.
Generally 3-5 of whatever I'm currently working on, but I also have my most visited sites on speed dial or they'd be up there too. Having too many open at once annoys me as less of the page title is exposed.
3 or 4 max
Immediately on start up, none. The five I immediately open are in my Speed Dial.
I almost never see anything on startup but my speeddial (5 x 4). If I need a collection of tabs accessible for later, I use saved sessions. I think I have fifteen or sixteen saved up right now.