Is there any help on initial data setup Especially for EXcel Imports. As from other database work I have done if the data structure is rubbish the output is difficult to manipulate or impossible in some cases.
also is it best to keep calculated data in excel or try and do all the calcs in tableau.
You can do some work in Tableau, but I always prefer the "data dump" format - just plain data in columns no fancy cross-tabs, formatting, etc...
Depending on the calculation, it can be done in either place. Again, I prefer Tableau but it's a personal preference.