Having your server visible from outside your lan requires it being accessible.
What is your connection (DSL, Cable, - Dynamic IP, Fixed IP)?
Do you have a router / firewall?
Have you configured port 80 to be forwarded to the proper machine?
Sorry, more questions than answers, but you will need to know these in order to set it up.
Also, a more descriptive Subject Title in your post might get more responses
"Still trying to shoot down that Red Baron"