The Guild Help reduces the timer of your building construction or technology research by 1 minute. You must join a guild to receive Guild help.

When you upgrade buildings or research technologies, after you tap the 'Upgrade' button, a 'Help' button will show up and by tapping it, you will send a Help request to your guild chat, which will be displayed as a Help request in the Guild Chat. 

Each time a guild member clicks the Help button in the Guild Chat, it will immediately reduce 1 minute off the timer of the requested task.