It is often a big time in a gay person's life, and it is important to remember that you should make up your mind whether to tell other people or not.
Some people come out at a very early age, others later on in life, and some never at all.
My personal experience with coming out has been mostly positive. All of my close friends are supportive and understanding. They have been great, and helped me out when I have felt bad. I also told my parents fairly recently, and their main reaction was shock. They have had a rough time trying to accept it, but I understand that it is their problem and not mine.