Why do you need my birth time?

The Ascendant or "rising sign" is the sign that was rising up over the eastern horizon at the time of your birth. Your Ascendant sign at the hour of your birth provides information on how you "appear" to people, how you present yourself, your physical attributes (a lion's mane of hair of a Leo rising, dimples for a Libra rising, a 'barrel chest' and slower gait of a Taurus rising, and so on), and how others perceive you - at first. It's only after someone gets to know us over a period of time that they start to see past "the mask" (rising sign), separate the wheat from the chaff, so to speak, and get to know the inner you. Time of birth can also be important in calculating one's Moon sign. A Libra rising is a sunny disposition; add a Scorpio moon to it and you have a friendly, warm person who is able to be discerning and astute at the same time. Also, as our Moon is related to how we think, as well as provide a good indicator of compatibility in personal and business relationships if favorably aspected with a partner's chart.  
What if I don't know my time of birth?
Many people don't know, off the top of their head, their exact time of birth and may have to look at their birth certificate. In some countries, birth time is not logged or may be slightly inaccurate. If your time of birth is unknown, I will initially use 12:00 p.m. and then, gauge your ascendant once I view your chart and get a bit of feedback from you. Your chart will still be 90% accurate even if you don't know your time of birth.

Why are my ascendant/rising sign and moon sign important?

The more you are in sync with your natural rhythm, the more others will feel comfortable around you. When you're in harmony with your rising sign, you experience the world in a way that feeds your inner spirit. This does wonders in terms of bringing synchronicity for the types and timing of events and beneficial relationships in your life. Some people we just seem to 'click' with, right off the bat - be it a kindred spirit or chemistry or both. Understanding one's ascendant and moon signs can guide you in decision-making about what course to take in the long run. Which brings me to the next question...
What are compatible aspects, and how do they affect a relationship?

Whenever the Moon sign, Sun sign, rising sign, or Venus sign form a conjunction with the same very placement of another (i.e., your Moon = his Moon), or with one of the others in that group (i.e., her Sun = your rising sign), it is especially favorable for compatibility. Mars-Venus aspects can be great for relationships and especially chemistry, as are Moon-Mars and Moon-Venus aspects. Mars-rising sign placements can be filled with chemistry. As always, the "big picture," rather than one or two isolated details, must be taken into account. 
What about free will?

The science of astrology has been around for ages, literally, and has a proven track record. As with any science, a good astrologer will look for patterns, trends, and themes in a person’s life and factor in timing. Everyone has innate strengths as well as areas in which they can improve. As a professional astrologer, when I give you a forecast for the future, it is to guide you as to beneficial, auspicious times as well as periods during which a bit of caution would be wise. There is, of course, plenty of room for free will; you are the master of your heart. Astrological influences exist; yet, they can develop in different ways depending on one's culture, frame of reference, etc. If your goals or plans might conflict with an upcoming planetary aspect, we can discuss ways to work with that or even come up with a better idea based on your personal strengths.

What should I do to prepare for a reading? 

In addition to providing me with your name, birthdate, time of birth, and birthplace. I ask that you jot down a list of any questions you may have. Especially with forecasts and progressions, this keeps a reading more focused in terms of your immediate goals and desires. It is perfectly fine, and even expected, that more questions will arise during the course of a reading, but it is helpful if you write down the important ones so we remember to cover them.