On the boot issue, Window Vista was one of Microsoft's biggest blunders since Window ME. The easy universal way to set up a multi-boot system with any version of Windows and (almost) any distribution of Linux is to keep them on separate drives
. The key word there is "seperate"
, so that they can't interfere with each other. If you can't install another hard drive inside your computer, you can buy a USB external drive and most Linux distributions will be happy with that. Just make sure your computer can boot from USB.
In any case, before installation, unplug the data cable from your Windows drive so that the Linux installer can't see it. When installation is complete, plug the data cable back in, and you are ready to reboot. In the case of using an internal hard drive for Linus, you will have to mess with your BIOS settings and specify which hard drive you want to boot from. If you used a USB hard drive Linux, then you just have to set the BIOS to boot from External or USB devices first. You need to check the exact wording within the BIOS setup menus. When in doubt, search Google and look for the manual.
After you get everything set up and verify that you can safely boot into both Windows and Linux, then you can change the boot menu for GRUB and add an entry for Windows. I suggest checking the man pages ("man grub" without the quotes in a Linux terminal) and the Wikipedia article(https://en.wikipedia.org/wiki/GNU_GRUB
) for more information. Specifically, search for something called "chain loading", which allows GRUB to pass control to a different boot loader (the Windows Vista loader).
Now for the "which distro" portion. Based on the wording of your post, I'm going to assume that you are just starting out with Linux. Indeed, Debian is a rock solid distro, so long as you stick to the stable branch, but most of the software is a few major revisions behind other distributions. You'll also be waiting a while for another "stable" relase (1 to 4 years). For a more modern alternative, you could try Arch Linux
. The installer is text based, you have to manually set up Xwindows, which is the "base" that GNOME, KDE, etc, sit on top of, and you have to spend a lot of time reading documentation.
Arch is more geared torwards advanced users, but system configuration is done through only a few files (rc.conf being the big one), the package manager is easy to use (though command-line only), and the software is always up to date (no fixed release cycles). If you still want something Debian based, you could try the latest version of Linux Mint. Ubuntu is another option, but the latest 11.10 release actually seems to be unstable.
Closing with the kernel thing, I have absolutely no idea what you are talking about. I always stick to whatever kernel the Linux installer puts on my system.