I'm still learning how to set up the car in F1RS. When I get better at it, I plan to write more about it here.
Until then, you might want to review some of the same information and tools I'm using. Some of these are intended for GP2, so specific numbers differ, but the general concepts are the same.
Note: Doug Milliken tells me that Amazon and Barnes and Noble don't stock his book, so it can take a long time to get it if you order from them. He recommends ordering directly from the Milliken Research Associates site or from the SAE. He also notes that many other good racing books are available from the SAE site.
For related information see my page on Indycar setup.
Look for expanded information here as I learn more.