You don't say if you are trying to access the web site for intranet or Internet use.
If you are trying to gain access from the Internet, then you would need to open up port 80 on your firewall. If you use SSL then you also need to open up port 443.
On the intranet side of things, you should not need to open up any ports on your router or firewall. Take a look to see how you are trying to access the site. Verify that your start page appears in the Documents tab of the web site properties.
If you are getting any errors then post them along with more details so we have more to work with here.
I hope you find this post helpful. Please let me know if it was.
Regards,
Mark