You can only fit 5 Peasants on a Gold Mine. Do not attempt to place any more on a Gold Mine.
Go here for a listing of buildings available.
Peasants build on the outside of buildings. This means that the enemy can kill them while a building is being
constructed to halt its construction. Command multiple Peasants to build a building if there is a risk they may be
destroyed while a building is being created.
Peasants can create buildings much faster by commanding multiple Peasants to create a building. Simply select Peasants and
right click on a building that is being constructed. The Peasants will move in and will speed up the construction of a building.
It will cost additional resources to build a building faster and Peasants working on a building will not be gathering resources so
it is not always a good idea to speed build. Only Peasants can speed build; the other races cannot speed build.