This site provides an overview about several simulateable aspects for almost all specs in World of Warcraft using SimulationCraft. These overviews are an entry point. You can also generate your own charts by becoming a Patreon.
For indepth information about your spec use your theorycrafters guides.
Pre-patch (level 50) simulations are trickling in.
Level 60 simulations are still on hold unless you're a patron and provide your own custom profile for your personalized chart.
SimulationCraft is an open source project and is always looking for help.