That is free and or cheap. I just got a new job and need to really lean this stuff in the two weeks before I leave for Georiga. Oh are there any Autopians in Alpharetta, GA maybe we could meet!!
not sure what sort of detail you're looking for, but a search on google with the phrase "excel tutorial" gave me quite a few hits...here are the first two
Look mostly for .edu sites as they're usually free and cover the bascics people need to know to function...for the advanced stuff, you''l probably need to buy a book