1). I've heard that before you can have your computer be a webserver (at least for a website) you have to have 2 static IP's from your ISP. Is this true? Would I be okay with just the one I have now? I am running cable 'net.
You need one IP. It helps if it is static. If have a cable modem, you may already have a static IP. You can go into your router setup and click on 'refresh DHCP' which will cause the router to hot the cable company and try to get a new number. If it comes back the same number. You probably have a static IP. Cable companies say they dont give static IP's. But this is a legal issue. Mine has ben the same for 4 years.
If you dont have a router, check you IP and the lease time on it using IFCONFIG. When the lease time is up, check to see if it renews to be the same number. If so, you may have a static IP. Unless the cable company claims it to be static, they can change it at any time without telling you so its up to you to deal with that.
2). Is there a tutorial for starting a webserver that I don't know of because I haven't been in the linux community very long?
The webserver you will find the most documentation on is Apache. O'Reilly has a very easy to read primer on Apache that is writen for newbies. It is called, strangely enough, Apache. www.oreilly.com.
You can find tons of info by googling apache as well. http://www.apache.org/
3). How rabid must one be in securing the server? Would a firewall work or is there lots more that goes into the process?
A firewall helps keep the box from getting hacked. It does nothing for the webserver. Ask yourself, if the box got hacked, what is the worst that could happen. For me the answer is I would havce to reload to OS and reinstall all my backup files such as configurations which I have on CD. Not bad. So I dont sweat it too much. If you have personnal or damaging info on the box, you cannot take security too seriously. The book Maximum Linux Security is a newbie to intermediate level book that will teach you tons about OS's, Linux, and also security.