How do I block websites, I am using Fedora Core 6, using Firefox 2, in Windows I know that a /etc/hosts files in system32 controls which sites are allowed or blocked by searching google. In Linux I found some host files in /etc directory. How do I use it or block sites another way?

The /etc/hosts works the same as the HOSTS file in windows, just add the sites you want blocked:
127.0.0.1 example.com

Of course you could also use dansguardian and squid to do the same thing, but that takes a little more to set up.

Every example I see has an IP then a website, is the IP needed, is it the websites server IP or is it the Networks IP.. the Network that isn't allowed to access the site?

Just to make the question simpler.. Do I need an IP and who's IP is it. If it is the websites and needed, no problem.

Example/part of my /etc/hosts file:

127.0.0.1 localhost.localdomain localhost
# This MVPS HOSTS file is a free download from: #
# http://www.mvps.org/winhelp2002/ #
#start of lines added by WinHelp2002
# [Misc A - Z]
127.0.0.1 ad.a8.net
127.0.0.1 asy.a8ww.net
127.0.0.1 www.abcsearcher.com #[Spamdexing][Microsoft.Strider]
127.0.0.1 www.acezip.net #[Win32/Adware.180Solutions]
127.0.0.1 adserver.adbunker.com
127.0.0.1 phpadsnew.abac.com

The hosts file in Linux (/etc/hosts) is a simple list of IP addresses and the hostnames that they correspond to. Every hosts file in Linux should have an entry for the IP address "127.0.0.1", with the name "localhost" following it. This is also known as the loopback address. That same file may also have an entry for your system name, unless you did not provide one during installation.

ok, so the IP is the same every time and is the localhost IP. Basically I just use the IP from this line 127.0.0.1 localhost.localdomain localhost and add the sites after.. is it possible to block something like *.*porn*.* instead of each individual www.crapornsiteinthe.net

You'll have to use Squid I believe.

/etc/hosts entries (or iptables OUTPUT chain rules) are a nice and quick solution for blocking just a few hosts.

Blocking something like requires more flexibility, and I'll agree with the solution that was already suggested several times: squid. It's well documented and lots of folks use it.

Well my hosts file is working OK.

I don't know how to use Squid, is it an external program.. because I cannot find a way to open it. If it is a part of SELinux then I don't know how to edit it for certain bans.

Also could I get it to ban say.. the word porn but still allow anti-porn...say?