This is the basic information to use the SSRS integrated in SharePoint, interesting reading for learning.
I have to ask about how the Report Server Database exactly works, there are so much things without answer in my mind.
Other important thing to be clarify: let’s talk about performance!!
The business case I have on my desktop does not require so much reponse time because the reports can be calculated during the night, but for on demand reports I would like to know if someone has done something similar.