well it looks like you are in for a few surprises, i mean you have to be prepared to at least reinstall your system a few times before you pick the distro of choice and get everything right. i generally advice to use a more newbie (like myself) friendly distro like mepis or kubuntu, i have even heard of some newbies being happy with xandros oce. i have tried it myself in the past but i don't like its package handling system. with the other two distro's i have never had any problems with the bootloader, particularly (k)ubuntu does a good job at recognising other linux distro's aswell as incorporate them correctly into the bootloader menu, mepis recognises itself and windows flawless, but ignores other distro's, however, this can be easily fixed when you edit the /boot/grub/menu.lst file. i have tried fedora, pclinux, mandrake, red hat, cent os but i wasn't too impressed, i think i am more a debian person. but no matter what distro you choose, you will have to be prepared to fiddle around to get it the way you want, but it is doable.