The Second House is the house of material resources: money, possessions, personal property, and the skills by which you earn a living. It is the house of value in the broadest sense: what you find valuable, how you acquire value, and how you maintain it.
In traditional astrology, the Second House is called the House of Substance. It describes not just money but everything that sustains life: food, clothing, shelter, and the means by which they are obtained. The sign on the cusp of the Second House, and any planets placed in it, describe your relationship to material security.
A planet in the Second House describes how you acquire and handle resources. Jupiter in the Second House often brings good fortune in financial matters, but also a tendency toward extravagance. Saturn in the Second House may bring financial struggle or scarcity, but also the discipline to build slowly and steadily. Venus in the Second House gives an appreciation for beauty and comfort, and often the ability to earn through aesthetic skill.
The Second House is naturally associated with Taurus and Venus: the sign of material stability and the planet of value. When planets are placed in the Second House, they take on something of this Taurean quality, becoming more grounded, more practical, more focused on security.