www.portforward.com is a good place to start, it walks you through it
but you gotta enter your router from your browser.
linksys use 192.168.1.1
d-link and netgear use 192.168.0.1
smc use 192.168.2.1
us robotics use 192.168.123.254
and a dsl modem/router could uses god knows what
then hit up that port forward section and add a new application to it, name it whatever (blockland) and set that port range to work from 28000 to 28030
for both TCP and UDP, enter your IP address in that other spot, and click enable, and apply.