ummm...word can save files directly to HTML. I have no idea what version of Word you have on your Mac but it should do the job. from there you can convert to pretty much any format using a wide variety of utilities. Even MobiPocket Creator, Plucker or any variety of document conversion apps specifically for word.

Personally would/will never find PDF's on this tiny display of any use at all. I am just not comfy with lateral scrolling. I find it interferes with digesting the content. Short of switching to a Tablet PC or a 12" laptop reading PDF's on the NIT's might be the most frustrating doc format around. Especially if the creator did not setup the doc re-flow correctly. Meaning the PDF is poorly created and does not include the ability to reformat for the given display allowing it to be read with anything smaller then the Hubble.

A couple problems you might find in using FBReader for research manuals is the lack of bookmarks and the lack of ability to add annotations. I love Fbreader but it still has a long way to go as a useful tool for research. But a pocket sized notebook works as a companion to the tablet seeing you already have it...

If you need info on converting books to fit better on the tablet there is a site dedicated to ebook devices and many folks there use N8x0's & N770's as their reading device. You can visit http://www.mobileread.com/forums to see what info you can find there.