If a hanging man forms at a resistance level, you should take notice of that level.
The Wikipedia description of Hanging Man below, while not being for traders, does explain how this candlestick was named which will help you memorize that this candlestick is bearish (i.e. its like Judas betraying Jesus but instead this candlestick is a betrayal of Bulls that had held the uptrend).
It depicts a pittura infamante (pronounced [pitˈtuːra iɱfaˈmante]), an image of a man being hanged upside-down by one ankle. This method of hanging was a common punishment at the time for traitors in Italy. However, the solemn expression on his face traditionally suggests that he is there by his own accord, and the card is meant to represent self-sacrifice more so than it does corporal punishment or criminality.
In other interpretations, The Hanged Man is a depiction of the Norse god Odin, who suspended himself from a tree in order to gain knowledge. There is also a Christian interpretation that portrays Judas, and include the bags of silver in his hands.