Hi:
If you use Stored Processes (SP) then you do not need to define Information Maps. That is one way to design your WRS reports. Remember that when the user clicks 'View Report' that each SP will then execute, and if you have input parameters set, the users will have to provide their choices for the input parameters before they will see the report.
Of course, if this is some kind of monthly or regular report, then perhaps you will not need to prompt them for input parameters.
However, one benefit of having Information Maps is that if your users wanted to filter on one group over another for a graph or report -- in an adhoc way -- they could do this if the WRS report was created from an Info Map. But with an SP, they do not have any interactivity or interface to the graph or the report itself except through the input parameters.
I'd recommend a few test reports to see whether the users prefer the SP version of the report or the Info Map based version of the report.
cynthia