First things first. Being a member of the LGBTQ community, (whether one identifies as lesbian, gay, transgender or otherwise) IS NOT A CHOICE! This is a common misconception that people who identify as heterosexual make. People who are a part of this community are natually who they are, the same way a straight person is naturally attracted to someone of the opposite sex. Secondly, there are a multitude of identities within the LGBTQ umbrella. Although there isn't room to go over them all, here are a few that people should have a basic understanding of.
Lesbian: A person who identifies as a woman and is sexually attracted to other women.
Gay: A person who identifies as a man and is sexually attracted to other men.
Bisexual: A person who is sexually attracted to both men and women.
Transgender: A term that encompasses transsexuals, cross dressers, drag queens, drag kings, and butch lesbians among other identies. These individuals transgress the socially constructed norms surrounder gender.
Questioning: A person who is in the process of self-discovery in regards to their sexuality.