1. Boot floppy: during installation you'll be asked if you want one. After that you can make more using the control center (i'm not too sure of the name that's been a while.. That's the graphical interface where you can change configs)
2. Linux doesn't need more than a few gbs to get going; besides that there is all the packages on the cdroms you really want to try out. With 10gb you can already go a long way. As of data remember you can also access your data on the Win partition. One more thing: you need at least 2 partitions : one for linux proper and one for the swap file (350Mb for 256Mb memory ram is ok). The linux partition is best kept on a primary partition (like Win C
. I prefer to use more than one partition for Win too . At least to keep my data away . These can be kept on an extended partition (this can be done using the XP partition manager). The Linux swap file can go there too.
3. Boot loader. Depends. There is several way to do it. Like you said you can work with a floppy. Using Lilo the loader can be put both on hda (that's the master boot record for the whole hard disk) and on a floppy. That's just a matter of changing a line in /etc/lilo.conf:
boot=/dev/fd0 vs boot=/dev/hda
and running lilo on that afterwards.
To be able to start Win from lilo just add
before running lilo always check beforehand !
#/sbin/lilo -v -t
If put on hda you can always get back at original loader using
from dos. In fact you are more likely to get the alternative problem where Windows resets the Master Boot Record to its original self and you loose your way to the Linux partition - that's where the floppy can save you the day. (That case happens everytime you reinstall Windows !)
When you asked for a boot floppy during install i don't think you get a lilo one, more like a grub one (depends on the distro). The principles are the same but i'm not familiar with the details. Read the docs (use locate to find them).Notice the term boot floppy is misleading: you boot from the floppy but the kernel image can be on the linux partition or on the floppy. When using lilo 'manually' you have to copy the image yourself. Usually the image on the hd is fine; that's only when recompiling the kernel that you get the problem..
You may also put the loader on hda2 (the linux partition) and then use an alternative loader like Ranish Partition Manager. This gives you more freedom to experiment with new OSes.
Remember : -always have a boot floppy handy
- if really stuck you can always boot from a single floppy/cdrom linux distro and reinstall the loader on your hd using the /etc/lilo.conf you already have
It is a bit hard at the beginning but when set up you won't understand what the fuss was about..