Hello I am a beginner when it becomes to most things Linux but i'm trying to learn a little more about hosting my own website, i'm curious to know whether I can have a domain name point to my webserver on a dynamic IP? I have BIND installed aswell if I need to configure it in any way. I have heard of some sites that allow you to do this but aren't free, is there any way I can do this myself?

I use Zone Edit to point to by webserver behind a cable modem and firewall. They have some info for us with dynamic IP here. Their basic service is free and easy to configure.

You can't run a DNS server like BIND as a resolving nameserver on a dynamic IP address (DNS server IP addresses need to stay fixed). You should do what meblost suggests or look into dyndns.org and like services for name resolution designed to work with dynamic IPs. You'll be using their DNS servers for their domain, as opposed to doing it yourself.

I have used no-ip.com myself, with no problems. no-ip and dyndns.org have little scripts that will update your ip info automatically, so you don't have to login to the website.

In addition to the other comments I would suggest that you check your ISP's Terms of Service. Some ISP's don't like people running web-servers/mail servers and will block incoming traffic on port 80 and port 25. With port forwarding you can work around this, but you still run the risk of them terminating your account (I assume they would give you a warning first though).

I've been running a web-server off an old PC at home for over a year (with an ISP that forbids running a web-server), and they have yet to say anything, but it is still something to consider...

But then there are very few things as gratifying as running your own web-server and mail server.

What if I was to use multiple domain names?

I'm not sure that I understand your question, perhaps you could elaborate.

Do you wish to have multiple domains pointing to the same website? Or do you want multiple domains each with their own website served from the same computer?

You can do it with multiple domains. I know since I've done it before.

Basically you just point domain1.com to nameservers that reside in domain2.com and vice versa. That way you do not need to specify glue records in DNS. The only problem is getting it started. Since one of those domains must be able to resolve initially to get the ball rolling.

After that it's not hard to write a simple script that can check your external ip every 15 minutes and if there is a change then update the zone files and reload the nameserver. Just make sure you set low TTLs on your records so the updates get pushed out faster.

I meant as in using a service like No-IP is it possible to use more than one domain name? say per website.

If I remember correct no-ip allows you 5 domains for free. Why not go there and have a look:
www.no-ip.org