This is a long one. Woo!
Well, let's run down the list of components in your sig:
The ASUS A7N8X appears to be fully compatable. I know there were some problems early on in the NForce2's life due to NVidia's stubborn refusal to release the documentation necessary to make an open source ethernet driver, but I think that's behind us now.
I don't know about what Mandrake specifically offers; it may or may not come with the NVidia binary drivers for your Geforce. If it doesn't, the installation program from NVidia is simple.
DDR is obviously no problem.
Any modern IDE CD-ROM drive ought to be compatable. So should the hard drive
Overclocking shouldn't be an issue either. You'll do it through your BIOS for the CPU and FSB, and NVidia graphics cards are OCed using a program called nvclock. They may not have 5x00 support yet, but they're working on it.
The Audigy 2 is supported by the ALSA project. If you're using advanced features of the card, you may want to ask around about how to use them (I personally am not experienced in that area).
Wireless chipsets are a different matter. Some chipset makers are real asses, like TI, and will release jacksh*t about their cards, making drivers impossible. Fortunately, you don't have a TI chipset. You have an Atheros chipset, and the mostly-open source driver is rather mature. The name of this driver is MADWIFI, and building it is easy enough (if it doesn't come with Mandrake).
The essential lesson of buying hardware for a Linux system: do
thorough research. And even then, hardware companies have their ways of throwing in little surprises.
---You can skip this if it's too confusing or you don't care about history---
Now, as for software: I'm going to start at the graphics layers. Linux and most every other UNIX clone uses the X Window System, which has been around since 1984. It is on its 11th version, and this version is on its 6th major revision. Thus, it may also be referred to as X11, X11R6, or even just X. A program called an X server is basically responsible for actually drawing pixels on the screen, though most can do so much more than this.
The library used to interface with X is verbose, so programming in it is discouraged. Thus, we have toolkits which abstract the interface, allowing us to create windows, widgets, and user interfaces. The two major graphical toolkits are GTK+ and QT. Programmers are the ones who decide which toolkit to use.
Now, an X server does not by itself give you a managable desktop. You need a helper program to keep track of the state of various windows you open and to allow you to manipulate those states. This type of program is called a window manager. There are tens of popular window managers, from the elaborate (Enlightenment) to the lean (fluxbox).
Now, for many years, most UNIX desktops stopped there. However, due to the influence of Windows, Macintosh, and other environments, which tended to be rich in helper programs, another step has been added: the desktop environment. There are two major ones in use today: KDE and GNOME. Usually, the popular distros will choose one or the other as its default; I think Mandrake uses KDE.
The desktop environment adds yet another layer of abstraction, which decidedly integrates the desktop. For instance, KDE is a collection of programs that uses the QT toolkit and its own special window manager to give the user easy-to-use functionality. You can change the look and feel and other with dialog boxes instead of configuration files. You can add helper programs to menu bars, such as volume control, battery life, etc.... You have programs like a character map, a basic text editor, a filesystem viewer, and other such useful things.
---Start reading again---
OK, so what programs are which?
Konqueror or Nautilus replace Explorer
OpenOffice.org will replace Office except for Access and very advanced Excel work (each DE has its own office suite as well)
Firefox, Galeon, or Konqueror will replace IE (basically, anything except IE and Safari are available on Linux)
Thunderbird falls somewhere inbetween Outlook and Outlook Express, pending development and integration of the Sunbird calendar; Novell/Ximian Evolution is definitely an Outlook replacement.
MPlayer and Xine (and various frontends) play your media.
That should get you started. A few pointers:
- Depending on how technically inclined you are, you will at some point find the console. Don't make the mistake of calling it a DOS prompt clone. It is so much more powerful than any GUI or DOS.
- The order of seeking help is generally as follows: man page, info page (especially if its a GNU program), README and other program documentation, program's website and FAQ, the Linux Documentation Project HOW-TOs, search online forums, ask on online forums (LinuxQuestions is good in general for this), and finally ask the program's developer. You should never exhaust that list for any one problem. And, of course, there is always the source. Use the Source, Luke!
- So, you probably want to know about games. In addition to the very many small-time games and clones of old small-time games, there is Nethack, which is IMO the most complex game ever to be written in code (not to mention a classic); and I have found LinuxGames and Tux Games to be most useful when it comes to commercial games. Oh, and all of iD's game engines from Doom up to the Quake2 engine are GPLed, and so there are many updates of those engines that enhance the game, for those times when you feel like it.
I think I have sucessfully inundated you. Hopefully I have not belittled your technical skills. Have fun and good learning!