Here some reference I founded while playing and browsing around the web.
Hope it’s help and if you have anything that could be added here fill free to share it in the comment.
Clash of Kingdom References
Google Doc spreadsheet on Clash of Kingdom References Heroes, Formations, Skills and units.
Heroes
Guide
How to march to battle (deploying troop and setting your combat settings)
CoK Academy Quiz
Every player will get 5 chances to do a Quiz each day, There located in the City Academy of your manor. Make sure to do these everyday to get 5 free Basalt gem.
You can find answers in the forum is you click here.