Gald you're looking into the Wonderful World of Linux!
To answer a few of your questions:
Making Linux look like XP is possible. There's a project called LXP which does just that. I haven't used it myself, but it looks good.
Project Page: http://sourceforge.net/projects/lxp/
Additionally, many people coming from Windows like KDE, one of the most popular desktop environments in Linux today. http://www.kde.org/screenshots/
Even better, one of the most popular (if not the most popular) Linux Distribution today is Ubuntu, which has a KDE version called Kubuntu.
Ubuntu Screenshot: http://en.wikipedia.org/wiki/File:Ubuntu.png
Kububtu Screenshot: http://en.wikipedia.org/wiki/File:Kubuntu-...iscreenshot.png
Get Ubuntu: http://www.ubuntu.com/getubuntu/download
Get Kubuntu: http://www.kubuntu.org/getkubuntu
Now, as for running Windows programs under Linux, there is a way to do this most of the time. It's called WINE (which stands for "WINE Is Not an Emulator") WINE has been in development for over a decade now and recently reached the 1.0 milestone. I've used WINE to run many games, productivity programs, and other applications under Linux. There will always be Windows programs that don't run correctly under WINE. You can check http://appdb.winehq.org/
for the programs you're interested in to learn what others have said about using them under WINE. WINE is available from most Linux repositories (Distribution specific databases of free software that can be directly downloaded by Linux and installed automatically)
All of this can be a little overwhelming at first, but once you get the hang of the basics, everything else comes easily. There are literally thousands of people out there just waiting to answer your questions and concerns. Most major distributions have thriving support communities (like http://ubuntuforums.org/
for Ubuntu, http://forums.opensuse.org/
for openSUSE, http://kubuntuforums.net/
for Kubuntu, http://forums.debian.net/
for Debian, and so forth.)
If you're still a little wary of taking the plunge, worry not! Most modern distributions have LiveCD versions built into their installer CD/DVD. A LiveCD runs a fully operational version of the Distribution without ever touching your hard drive. Once you reboot and take the CD out, it's gone and Windows never is the wiser. Also, some Distributions can install INSIDE Windows through a program call WUBI. Ubuntu includes WUBI on their CD so all you need to do is insert the CD while in Windows and select the WUBI option. I've never used WUBI myself, but I hear good things. Another possibility is to use a Virtual machine. Many VM programs are available free of charge. I've used both VMWare (http://www.vmware.com/
) and VirtualBox (http://www.virtualbox.org/
). These programs will create an entire virtual computer with which you can do anything without breaking Windows (they also run under Linux, BTW)
Good luck, and don't hesitate to ask questions!
PS: Bleeping Computer has an excellent beginners guide to Linux by one of our resident Linux Geeks, yourhighness: http://www.bleepingcomputer.com/forums/t/100007/an-introductory-guide-to-linux/
Edited by Amazing Andrew, 16 December 2008 - 01:09 PM.