If you are using the latest of a big distro, Mandrake, Redhat, SUSE, it's a dodle. see the MES FAQ for lots of dual boot stuff. With mandrake you can configure internet during installation, and then you are up and running. If it's not dual boot, then put the cd (or boot boot floppy) in the drive and off you go.
For hardware compatability you should head over to the distribution's website, and they will have a section that you can check you hardware on.
For NTFS - NO you will need FREE SPACE, Linux will format that space using it's prefered filesytem. NTFS is a M$ proprietary FS, and you cannot install Linux on it. If the hardrive is currently NTFS and you are not dual booting you can just tell the formating program to wipe the old filesystem. Hunt around this forum for dual boot info - there is a lot of it, and it is really very easy.
two things.
Backup all your data
and if dual boot - defrag the windows filesystem, because windows places file fragments all over the space alloted to it, and defragging it puts it all closer to the start of it's alloted space. nad then resize it to make your free space.
edit - NTFS stuff
[ December 07, 2002: Message edited by: Linux Frank ]