Let's Get Something Straight: Definitions

First, let's get something straight: Bisexuals and transgenders are not the same as homosexuals. Transgenderism is not an issue of sexual preference but rather gender. Transgenders, just like everyone else, may identify as either straight, bi, gay, or anything else (in fact, until the 1700s, there was no evidence of linkage between cross-dressing and sodomy). Bisexuals are not monosexual, clearly, meaning they are not polarized onto either side of the gay or straight spectrum.

Here are a few sexual preferences/gender identities. Keep in mind that not everyone likes to restrict themselves with labels. 

Queer: An umbrella term for sexual minorities. Since it started out as an anti-gay slur, its use among LGBT is controversial, seen as self-deprecating to some but a reclaimed term to others.

Transgender: The state in which ones gender identity (self-identification as woman, man, neither, both, etc) does not match ones socially/physically assigned sex. May identify as FTM (female to male), MTF, agender, bigender, third gender, or genderqueer/fluid. 

--*Not* an identity, though often confused: Intersex: Uncommon variations of biological sex developmentation.

Transsexual: People who identify and live as a member of the opposite sex assigned at birth. Many undergo gender transitioning, which can include gender and sex reassignment as well as hormone replacement therapies. Afterwards they may refer to themselves as that gender as opposed to transsexual. Unlike transgender people, a transsexual's subjective gender will match their apparent gender.

Bisexual: Often defined as one who has an equal attraction to both males and females, though in reality it represents a large spectrum between the gay and straight polarities. The majority of bisexuals are unequal in their attractions to each gender, and these levels of attraction are often fluid and constantly shifting. Most bisexuals are not genderblind. Depending on which culture they relate to more some bisexuals refer to themselves as gay-identified or straight-identified. 

--For more information see the KINSEY SCALE

Asexual: A lack of sexual attraction/interest or desire for sex.

Pan/Omnisexual: The potential to like people of all gender identities and biological sexes; unlike the majority of Bisexuals, some Pansexuals may refer to themselves as gender-blind, basing their attraction on a person's personality as opposed to physicality.

Polyamorous: Non-monogamous; being in a relationship with the knowledge and consent of multiple people at one time.
--*Not* polygamy/polyandry, which means to have multiple spouses who have no sexual bond between any person but the head spouse.
--*Not* cheating- often a long term, committed relationship as part of a triad, quad, or intimate network.
--*Not* bisexuality, though statistically there are more polyamorous bisexuals than homosexuals.

Ambigender/Androgynous: The combination of masculine and feminine characteristics in one person, be it in terms of fashion, sexual lifestyle, physicality, or personality. They do not fit cleanly into the typical male and female roles of their society. Some define themselves as genderneutral, non-gendered, pangender, or gender fluid.
--For more information see the Bem Sex-Role Inventory

Questioning: A person who is exploring their gender, sexual identity (including sexual characteristics such as breasts), sexual preference, or all three.

Bicurious, Homo/Heteroflexible: When someone experiments/shows curiosity in relations with the gender they don't generally favour.

"I could go on, but the point is that the number of orientations in this world is limited only by the number of people in this world."