If you don't have another working Mac, you will need a floppy drive to proceed, so beg, borrow or buy one (they're all over the place for free, essentially -- check craigslist, surplus shops, garage sales, etc.). If you live in Silicon Valley, let me know. I'll give you a bucket full.
Once you've gotten that far, head on over to http://home.earthlink.net/~gamba2/pc2mac.html for instructions and software for making mac-readable disks on a PC.
Then, go grab a bootdisk from Apple: http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/System/Older_System/
After you've successfully made a bootable floppy, run Disk First Aid (it's among the files from Apple). It's not a full-featured program, but it might be enough to fix your problem. If that doesn't do it, you'll need to search for more industrial-strength recovery programs, like Norton Utilities.
You'll be up and running in no time!