Ehh, I didn't post my site on Tamagotchi Topsites (yet), so I'll try to help you out as much as I can.
I think, right after you register to Tamagotchi Topsites, your site starts off at the very bottom of the charts and it will have to work it's way up. Either that, or you have to log in to your Tamagotchi Topsites account and manually post it on the boards.
I'm not too sure, but that's what I was thinking Hope I helped (a little)!