Sounds like the port isn't open. Here's what to do:
1.) Open a Terminal, switch to root
$ su -
Password: [Enter root password]
2.) Check to see if port 80 is open
# iptables -L
You're looking at the first block where it says 'Chain INPUT (policy ACCEPT)', see if there's a line that looks something like this:
ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:http
3.) If there is no such line, you have to add an entry to the file that is loaded at boot into iptables
# nano /etc/sysconfig/iptables
Look for the following line:
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
Directly under that, let's put a new line that will define the rule to allow traffic to the webserver:
-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
If you plan on using https:// on your site, you'll have to add this too (on a new line):
-A INPUT -m state --state NEW -m tcp -p tcp --dport 443 -j ACCEPT
Hit Ctrl-X to exit, then 'y' to confirm the changes, then 'Enter' to save under the same filename.
4.) Restart iptables
# service iptables restart
Now if that doesn't solve your problems, please check your log files as suggested earlier.
Hope that helps.