An Archer rush in AOE2 is where you build your economy in order to advance to the Feudal Age and then attack quickly with archers. Usually an archer rush build order is completed at 22 or 23 population in AOE2. Your main goal should be to damage the enemy economy by killing their villagers. Target the places that they are collecting resources from such as gold piles, woodlines and berries. An archer rush is one of the best strategies to use at lower levels, before advancing to a Man-at-arms rush. The main counter unit to archers is the skirmisher as they inflict bonus damage to archers. Scouts can be a problem in larger numbers but 6 archers with fletching should defeat 3 scouts.
Here are the best civilizations to complete an archer rush with:-