I love spreadsheets for evaluating the relative financial feasibility of a deal. It just helps me to take the personalities out of the equation for a little while and run some scenarios.
I have a fairly basic and flexible version (See Link) that I thought might be a helpful place to start if you are thinking about monetizing a content based (i.e. "eyeball" or advertising based) business.
**Hint - don't start unless it looks REALLY good because no one ever seems to meet the pro formas (at least not in the short run).
For more in depth help (or if you are a Spreadsheet Jockey in training) there are any number of books, etc. available.
