You are in almost the exact situation I am in. I just installed Slackware 9.1 a few days ago. I am dual booting windows xp and slackware off of a 40gig harddrive. This is what I did:
Partition 40 gig harddrive using partition magic into 30gigs NTFS, and 9.5 gigs FAT, leaving an extra .5 for the swap drive. I already had windows installed on the HD, so I just rebooted and booted from the slackware CD. I just followed the installation, which might I add was actually very easy to do if youre semi-competent with computers in general, and that was that. During the first install though I set it to boot from a floppy, but I went back and fixed it to use LILO. One thing I might add though, I read from a few different places that your swap drive should be 2 times your systems RAM. Ive got 256 ram, so I made a 512 (well as close as it could get) swap. If you had 512 ram, consider a gig swap drive. Other than that though, your plan sounds fine.
As for the reading materials, I have been searching alot too. The very, very best thing I have found so far is this:
This site is by FAR the best I have come across. It isnt specifically for slackware, but rather linux in general. Its ALOT of reading though (several hundred sections), but its incredibly in depth. I am just starting chapter 8 now and already I have learned an incredibly amount, just in one night. I HIGHLY recommend it.
Also, something I found out the hard way... when you install slackware, your default sound is set to mute... to unmute it you need to type alsamixer from inside a shell and unmute and/or turn up all your channels. If I had known this when I first started it would have saved me several hours of looking for/installing/configuring drivers I already had. Good luck.