Here's another post in response to a reader request; a quick and easy guide to what the 12 Houses represent. This is not an exhaustive list, but I've tried to cover the major areas. Note that when I mention influences on these houses, the possible effects are entirely dependent on the planets involved (natal and transiting/progressed/solar arc).
1st House: The "you" that people first meet, but also your identity. Influences on this house can impact your energy level/vitality/mood. Your physical appearance, how you interact with the general public.
2nd House: What makes you feel secure and what you do to maintain that security. Personal values, earned money, resources you own (material and emotional). Your personal sexual energy. Influences on this house can impact your wealth, self-esteem.
3rd House: How you exchange information with others. Communication, thoughts, messages, speech, short journeys, your neighbourhood. Influences on this house can impact your mental health. Also represents siblings and cousins,
4th House: Your roots and childhood. Associated with the family in general, but with the father specifically. Wherever you are currently living; your physical residence. Influences on this house can indicate relocation, purchase of a house, home repairs/decorating, retirement, career change (opposite from the 10th House), additions to the family or death in the family.
5th House: This house is associated with children; your children, children in general and the child inside of you. It describes how you express your ego and what makes you special. It also rules performance, artists and creativity. This is the house of romance, but new/uncommitted romance only (committed relationships are ruled by the 7th House). Games, parties, gambling, fun, flirting. Influences on this house can impact your potential for conceiving/giving birth.
6th House: The house of "what needs to be done". Daily routine, your health, service to others, service people, anyone in the medical profession, pets. Influences on this house can impact your physical health/energy level, duties you perform for others and services people perform for you. Because this house represents your daily environment, influences can sometimes indicate a job change.
7th House: The house of formal partnerships (romantic and business) but not relationships with blood relatives. Because this house is opposite from the 1st, it also describes your qualities that you project onto others. Influences on this house indicate what kind of partner you are, what energy dominates your partnerships and upcoming serious relationships.
8th House: This house covers what you don't have control over; it's the house of personal vulnerability. Also associated with psychology. Shared resources, debts, taxes, loans, your partner's finances, inheritances, emotional intimacy, death. Opposite from the 2nd House, it represents the esteem your partner holds for you (as opposed to your self-esteem), and the sexual energy you share with another.
9th House: The house of broadening your horizons. Long distance travel, anything foreign, legal matters, higher education, guidance from others (lawyer, priest, teacher, guru), philosophy. Teaching/mentoring ability can be shown here. Influences on this house can indicate relocation to another country.
10th House: Career/vocation, potential for fame, your boss, your official status, your mother. Influences on this house can indicate major career change and (sometimes) important changes in a parent's life.
11th House: Opposite from the 5th House, it shows how you run with your personal goals/wishes/hopes. Note that the 10th is professional ambition and the 11th is personal goals. Also represents friends, groups, allies. Influences on this house can impact the number of friends you have and how you handle yourself in group situations.
12th House: What's hidden, held back, unacknowledged, yet to be revealed. Spirituality, dreams, the unconscious, transcendence of the physical. Also associated with isolation and convalescence. Influences on this house can indicate major endings, lifestyle changes, secret love affairs, psychological issues.