sartre said:
How do you donate? I see how to request (and within seconds I had some donations!), now I need to learn what to do with those troops, and how to reciprocate.
When someone else requests, the chat window will show their name with a Donate button. Click on it, and it brings up a window with your troops on it. Click on the ones you want to give.
To use the troops on defense, if you're offline just leave them in your castle, and if an enemy shows up inside the white radius you see when you click on the building, they leave the castle to fight them.
To use them on offense, when you're actually doing the attack, you'll see the clan shield as one of the options of types of troops you can deploy in the battle. Just click on it and and on the map and they'll spawn at that location.