I was looking for the way to improve statistics from Edgesight database and I found this excellent website  with a guide to use reporting services and making something from it.
Part 1 : Making Citrix Stats Work for You Part 1
Part 2 : Making Citrix Stats Work for You Part 2
Part 3 : Making Citrix Stats Work for You Part 3
Part 4 : Making Citrix Stats Work for You Part 4
Part 5 : Making Citrix Stats Work for You Part 5
Part 6 : Making Citrix Stats Work for You Part 6