IIS logs wont give you this info. You'll just get the owsvr.dll
(maybe mispelled) that is referenced everytime sharepoint grabs a doc.

There is a Report pack for sharepoint which attempts to actually be usable.
www.microsoft.com/.../details.aspx
i think it still sucks though, compared to other portal sw where you actually have audit trails OOB.

HOWEVER,

the route I would reccomend if you are just looking to monitor/log a selection of document  libraries/lists etc would be the handy dandy event sink thing. since im not a developer i wont pretend that i know much about it, other than i played with a sample from MSDN and it had a nice console application for seeing all activity on a document library.. im sure someone here knows which article im referring to.

at least i pointed you in the right direction im hoping,

I will check the link out. Unfortunately the event sink
code only works on transactions, insert update, delete, check-in and
check-out but not on viewing.