If you have a static DNS line, which I’m guessing you don’t unless you specifically requested it, you can establish your domain name using a variety of DNS services.
I use dyndns.org/. They have a free service for both static and dynamic addresses, but if you opt for their free service, your domain name will be a subdomain of their dyndns.org (like mydomain.dyndns.org).
If you want them to point directly to your static or dynamic domain name (like mydomain.org), it costs USD25/year.
If you have a static address, you can set up the domain name server on your linux box, for free obviously. The problem is that it’s a bit of a pain and even if you get it working, unless you really know what you are doing, you may be throwing little monkey wrentches into the domain name structure.
My understanding is that you can request a static address from your ISP for not a whole lot of money, like a couple hundred extra NT a month.
I used to have my dns server working on my linux box, then when I installed Fedora Core 2, available from http://fedora.redhat.com/, I was so busy at the time I decided I wasn’t up to configuring the DNS server. Also, I decided that since I didn’t really know what I was doing, the socially responsible thing to do was to simply pay for DNS service that (I presume) was being configured properly and that worked (I’m certain) efficiently. I’ve been very happy with service from dyndns.org.
The good news is that on your new linux box, you’ll find it fairly easy to set up all the other servers: ftp, html, mysql, mail, etc. For IMAP and POP3, use the Dovecot server. It’s not the default but it’s by far the easiest to configure.
Finally, I highly recommend installing Fedora if you’re going the Red Hat route. The Taiwan mirror site for download is located at IShou University, and the URL is: http://ftp.isu.edu.tw/pub/Linux/Fedora/linux/core/ for http and ftp://ftp.isu.edu.tw/pub/Linux/Fedora/linux/core/ for ftp. I downloaded the 4 discs at my college and they downloaded lightening fast. Maybe it’s the cocktails talking, but if you can’t download it, let me know and I’ll send you the discs.
Finally, your choice of using GoDaddy is a good one as far as I’m concerned. I’ve been with them for a couple of years and have had no problems. Of course, we always have good things to say about these services until something goes wrong, right? In any case, their prices are about as low as you’re going to get and their site and services are easy to navigate and use.