Ask your girlfriend questions about her life. This is the most commonly-used method of gaining more information about a person. Ask her questions over dinner, outdoor activities or over the phone. Start by making simple inquiries, such as "Where did you grow up?" or "Name one of your best experiences in high school?" As you and your girlfriend become more comfortable with one another, you'll each gain more information.

Listen to clues that she gives during casual conversation. You won't always have to ask her questions -- you can gain information about her family while the two of you are watching a movie, or learn about her favorite activities while planning an evening out on the town. Pay attention to personal anecdotes or stories about friends or ex-boyfriends -- these conversations will provide useful information about how she interacts with others.

Observe her home and personal spaces. When you visit your girlfriend's home, notice if she puts things in their designated places, or is a bit messy. Notice what kinds of foods she keeps in her refrigerator, and what books and movies she keeps on the shelves. Look at any family pictures that she may have hanging on walls, too. If you're ever in your girlfriend's car or other personal spaces, take a look around to learn more about her.

Ask your girlfriend's friends about her. Her friends will know plenty about her, and if you get along well with them, they may spill a few beans about their best gal. Ask her friends questions about her favorite gift items or her idea of the perfect date. Find out what they think you can do to please her in your relationship -- also, offer her friends a small token of appreciation so that they will continue to be a valuable source of information.