Ubuntu server download (9.04 server edition features) Ubuntu server setup documentation (7.10, 8.04, but that is fine) and FAQ
Also general documentation and Server Guide for 9.04
Ubuntu home server setup steps HowToForge: The Perfect Server - Ubuntu Hardy Heron (is about 8.04, should not matter) other interesting reads,
blog post on a user experience (has some other ubuntu article references)
while this general question was moved to SU, you can lookup specifics at SF
like, setting up remote access and logs that you should monitor
Since you are new to unix/linux environments, the UbuntuGeek site is a good reference Bonus: Chapter 5. The Ubuntu Server from The Official Ubuntu Book, 3rd Edition
What Is Ubuntu Server? Installing Ubuntu Server Ubuntu Package Management Ubuntu Server Security
Since you seem to have a single static IP address from your ISP for setting up this server, DNS may be more about configuring your web domain and server name properly. Even that might be solved by your ISP.
Things get more interesting if you intend to have a small network along with the server. You then need to protect the network from a potential server compromise too.
Here are a few references for DNS,
Linux DNS Server (this is a good read for general concepts) DNS Setup & Configuration in Unix also check this short quick-read on How to Set Up a Server"
"Setting up your own server does require you to decide upon a lot of things. As have been pointed out, pick a good Linux distribution that contains whatever you need. Unfortunately, at that point your work only starts!
When you use a LAMP system, much of the components will already been chosen for you. Linux with Apache is the natural choice. And for a home system an Oracle database is pure overkill so MySQL is a good choice too. Then you have to chose between PHP or Python, which are both used for web development.
When deciding upon which development language to use, you might find more practical advise at StackOverflow. Of course, if you use some ready-to-use product to just install on your system, things will become a bit easier. Will you do the software development yourself or pick some third-party products?
When picking some third-party products, you will have to check what you want to use on your system, exactly. Do you want a forum? A bug reporting system? A blog? A complete CRM system? A photo gallery? So many options to choose from. And whatever distribution you pick, you need to configure it to fully support this product. (Fortunately, almost all products will install nicely on almost all distributions.
And then you have a server, running the software you like. And at first you get 5 visitors per day, and things run fine. Then more visitors will arrive and amongst them, some will be spambots and hackers, who will try to misuse your system. You will need to moderate your server a bit more, especially putting a stop to possible hack attacks. If you run a forum or blog, you'll need to do something about the spam messages and spam comments that will pop up sooner or later. Soon it becomes too much for one person to handle and you will need a few friends to help you to moderate your site's content.
Don't think that you're done once your server is set up. At that point, the work just starts..."
