Dave -- Since you're using a modem and don't have a direct internet connection, I'd suggest ordering the debian cd's from i-connect (web = www.i-connect.net). The installation should go pretty smooth, although you may have to repeat the procedure a few times to get everything to install correctly.
However, if you're in the mood for adventure, to upload everything from the web using a modem, you'll need to get the "diald" package along with a ppp daemon (don't know if they're included in the base disk set). Get these in dos, transfer them to linux, and then unpack them using "dpkg". Then you'll need to configure them... Also, you may need more than just diald and ppp... Maybe it's just better to order the cd's from i-connect. To answer your specific questions -- To unmount the floppy, user "umount /floppy". X-windows isn't the next thing you need, since you'll need the base-level packages like the "vi" editor first. ".tar.gz" packages need the "tar" and "gunzip" utilities, etc. Your best bet is to order the cd :-). -- Harmon