Beginners' question about interference of GRUB with windows bootloader

[Aleksei]

Hi, sorry for spamming list with stupid questions but
I did not found any other obvious place (if there is one in the first
place).

I've installed GRUB Legacy, but since I have windows xp in my (hd0, 0)
I decided to start GRUB from a floppy. This because I do not quite
know how computer boots, I mean, if installing GRUB to my (hd0, 0)
will overwrite windows bootloader or not? I may go on with floppies,
but they tend to get lost or break down...

Moreover, I have Powerquest bootmagic also in hd0, it is not much
of use in general because it is not able to find my gnulinux from (hd1, 1),
but it is useful when I travel with my first hard disk since crap windows
xp is not able to load with in alien hardware environment! (with bootmagic
I may select OS of alien computer).  Will installing
GRUB Legacy to my (hd0, 0) override bootmagic? Of course, that would
not be that much of a disaster, since I could always reinstall bootmagic
when travelling.

At some point, it could be useful to add basic information about PC booting
in general to GRUB documentation (for example, what is difference between
MBR and boot sector) to avoid this kind of questions.

As for the stupid questions, perhaps there could be a section in GRUB wiki
for them, in order to avoid plaguing mailing list...

Thanks, Aleksei