Well, what I did was partition the harddrive into 2 parts. First (this is important), install 98 on drive c. When that is all done and set up, install win2000 in drive d. 2000 will detect the other OS and and set up the dual boot options for you at boot-time automatically. If you need more details, just ask!
When I first did this, I installed 2000 first and then 98. The problem was that 98 did not detect 2000 and so I couldn't dualboot. What a mistake! Had to do it all over.
Hope this helps. If you wanna buy 98, I have a OEM copy still shrink wrapped. All legal and brand new. Giveme an offer.