You could try almost any book on SQL Server Analysis Services. However, I would point out that creating cubes, and especially querying cubes, is quite different (and in my opinion more difficult) than working with relational tables.
@roac I agree that it's more difficult and it's new to me. Right now I am trying to learn it. I wish I dun have to rewrite everything but there's too much data. There are millions of rows for one month of data and excel can't handle it when I connect it to the SQL database.