Are you aware of this function list?:
Are you looking to replicate investment banking hedging trading programs, or are you looking to do financial analysis the old school long term investment way?
For the old school stuff, I recommend two books:
Security Analysis by Graham and Dodd
The Intelligent Investor by Graham, Zweig and Buffett (yes Warren)
Another for anyone interested in general theory and philosophy:
The Essays of Warren Buffett: Lessons for Corporate America, Second Edition
If you are leaning more towards quantitative/computational finance, google the names on this list:
I would say Paul Wilmott is the big one. I like him because he is willing to criticize the field and its sometimes overarching models. I have a list of other resources and tools if this is what you want.
Another author who is a good read is Nassim Nicholas Taleb, he has some interesting links on his webpage:
In general with excel, look up the function on the list at the top, and if you have problems using it, google or youtube it, there are likely tutorials for them. It will take some work on your part to find what you need, but once you learn to apply it and refine your models, it gets easier.
My advice for anyone regardless of level or investing style is to read the Essays of Warren Buffett. It becomes a lot easier to ignore the up and down hype in the media/markets and focus on the true nature of business, enterprise, investment, and how it relates to long term returns.