If you get into your router config, there should be a section for port forwarding. Basically, you enter a range of ports (6881-6999 being the default BT ports) and specify the local IP address of the computer you want traffic to those ports to be forwarded to.
You access your router config usually by entering the IP address of the router in your browser.
ZoneAlarm and most other software firewalls works on a per-application basis. So if you just allow your BitTorrent client access, the firewall should allow traffic to/from all ports unless you specify otherwise, or the default ruleset is different.
I dont get it at all - Torrents I download from Suprnova work fine, but when I download from IndieTorrents, I cant share. I want to, or else I'll get banned. The only advice I get is to open my port, but its bound to be open is my Suprnova torrents are working.