If you have '98 as already installed as FAT32 there's your first problem to deal with...
In a '98/NT dual-boot the C: (active) primary partition has to be FAT16.
This is the only common format across all M$ OS's; and in a dual/multi-boot all installed M$ OS's install their boot/start-up files into C: ; the actual OS files (system files) can go into separate logical-drives... FAT16 is the only format that 'all' can see at boot time.
Post 3279 on the NT forum gives a viable way to set it all up - if willing to start afresh. Only addition I'd offer to it to include adequate data 'drives' for shared data; and they have to be FAT16 (as NT can't see FAT32, and '98 can't see NTFS - without you use add-in utils for '98/NT).
Otherway is to either use PM (current version 6x) to set it all up. It will require to have two separate primaries, an OS in each, and you use PM's boot-magic to selecet which (and thus the OS) to boot.
You will also need a common data area in the Extended partitions space if you wish to share date between the two primaries... Extended partition is visible to all active primaries, but inactive primaries are hidden.
Other option - a workaround that allows FAT32 in c: - it's at: John Savill FAQ's at:
http:/www.windows200faq.com
- check in the installations section; item you want covers the FAT32 and NT issue.
http://www.windows2000faq.com/Articles/Index.cfm?ArticleID=13902
is the item link you need.
Other boot-managers:
http://www.xosl.org
http://www.osloader.com
Also if your HD is greater than 8Gig you will need to address that too. Again John Savills covers it at:
http://www.windows2000faq.com/Articles/Index.cfm?ArticleID=13894
http://www.sysinternals.com
has utils for NT/'9x to see FAT32/NTFS respectively - they go in after the OS's are properly installed.
Once you have NT installed make the ERD; keep it up todate after each change to your system...