Ubuntu is a great and secure OS and here is some information for you.. My recommendation is to make your system a dual boot (easy instructions provided) and learn about Ubuntu before giving up on it..
I would not install with WUBI installer (installing from inside Windows) since it is buggy and Ubuntu runs slower... I recommend booting your computer from the Ubuntu LiveCD and read the instructions below to do this..
I would get Ubuntu 8.04 LTS (please note: The versioning is Year.Month which means 2008 . April release, every 6 months a new version comes out 8.10 is already out but it is too new)
http://www.howtogeek.com/howto/windows-vista/use-ubuntu-live-cd-to-backup-files-from-your-dead-windows-computer/ is meant for backing up a PC but it will get you started with downloading, burning a cd and booting up ubuntu without even installing...
http://apcmag.com/how_to_dual_boot_windows_xp_and_linux_xp_installed_first.htm shows how to make a dual boot system with Ubuntu (Please Note: Click on Page 2... Page 3... etc..)
http://screencasts.ubuntu.com/ Screencasts for Ubuntu
http://www.linuxfoundation.org/en/OpenPrinting/ Printers for Linux in general
https://help.ubuntu.com/community/SwitchingToUbuntu/FromMacOSX
https://help.ubuntu.com/community/SwitchingToUbuntu/FromWindows
Wine is a nice tool to run some windows programs but can e tricky to setup. http://www.winehq.org/ It has a database of windows programs that work http://appdb.winehq.org/
Wine-Doors makes it easier to work with Wine:http://www.wine-doors.org/wordpress/
Here is some information on how to install programs on Ubuntu...
http://www.psychocats.net/ubuntu/installingsoftware
Another Note: By default on Linux, you can only edit files in /home/{your userid}, to modify other files there is a fake root user that can be implemented with sudo or gksu.
http://www.debianadmin.com/linux-directory-structure-overview.html will give you an idea of how the file structure is on Ubuntu (Linux in general)... There is no A:, C:, D:, etc.. drives. The top level is /
Any questions, feel free to ask.