The Second House is related to our need for security. It covers money and possessions, and anything which affects our feelings of self-worth. It is also linked to those things which we do for pleasure, especially those which do not involve other people.
Planets in the Second House represent energies which are linked to our needs for attachments and security. For example, Mars in the Second House would suggest a reckless attitude towards money, while Jupiter in the Second House would suggest luck and expansion linked to the idea of money and resources.