There is a list of 41+ questions and answers on this site:
http://www.ilounge.com/index.php/art...ions-answered/
http://www.ilounge.com/index.php/art...ions-answered/
Both documents are a bit old, but it seems like Apple desires to sell you Pages or the iWork suite to interchange documents between your computer and iPad.
http://itunes.apple.com/us/app/pages/id361309726?mt=8
Beware the one-way street features of the above.
In a few days, we'll see what alternatives people come up with. I'll wait for the jailbreak solution, if there are no low cost apps to view and modify certain folders in the iPad filesystem.