Please, help me build a web server. For more information, please visit: SNIP

Hi there,

See below for answers to your questions:

Now, I need some help from you guys! Which operating system should I choose (Ubuntu Server, or something like that. For the time being, I want a free operating system). How can I install/configure the operating system and how to get it up and running? How can I install Joomla 1.5 on it (it needs MySQL)?

I would say look at Ubuntu Server with a LAMP (Linux, Apache, MySQL, PHP) install and then install Joomla on top of that.

And how can I install/configure email accounts for my domain?

Check out Zentyal (used to be called ebox)

I’ve also heard of a software called Webmin. What is this?

Webmin is a web-based interface for system administration of a Unix / Linux Server.

Is there any other software that I can use for managing my domains, files, email accounts, etc. (something like Parallels, or cPanel just that it needs to be free or really cheap, because I’m currently on a tight budget)

As I mentioned above check out Zentyal.... It's free :).