I'm learning too
hda is your primary IDE and hdb is the secondary IDE
your HD will get divided into various partitions hda1, hda2, hda3 and so on - so will the hdb but usually all you have on the secondary IDE is your CD-ROM , this will be hdb1.
If you run a dual boot system, hda1 will be Win or MS-DOS, apparently DOS can't run unless it has the early cylinders on the HD.
hda2, will be your LinuxOS and hda3 will be your Linux Swap partition.
I got Partition Magic (7.0) and it seems to do a reliable job of partitioning the fixed disk without osterizing windows. However, I'm not so happy about Boot Magic, I've had several Linux failures using it.
There is a Linux program, FIPS20 (I believe) that both partitions and provides a dual boot.
I got my system "working" (still work in progress) just by simply downloading several floppy disks worth of files from Debian as follows:
1) Fips20
2) Debian LILO (Linux Loader)
3) Rescue.bin
4) Root.bin
5) Driver1 thru 4 .bin
6) A bunch of iddy-bitty files like : rawrite, kernel, loadlin, install, setlang, deboot.
I also downloaded "woody-i386-1.iso", which is about 190 Mbytes of 'stuff'
It's a real learning curve and this only gets you a Command Line system. You'll need to get Xwindows from XFree86.org and after that a 'desktop' such as Gnome or kde.
Good Luck!
P.S. look for my Newbie questions, I'm not far ahead of you. G