I would first question how you know a person is not a woman - unless they specifically tell you that they are men, you can't tell by looking at them alone and if talking to them then ask THEM why they have marked themselves as women. I would guess however that in many cases it's just done by accident.
Somtimes amiguous, usually obvious. And sometimes even the username, incorporating their real name, is a giveaway.
Try ozteen.net or ourteennetwork.com
Local LGBT events are really good for finding Transgendered people. You can find these online I am sure, and you can also go on specific transgendered dating sites which you can also find using any search engine.
some teenagers are to young to be on dating sites. These sites are for older people who can handle themselves and know when some one is getting out of hand. i personally think if you are mature enough then you can go on a dating site if you are 16 and older.
To learn about online dating, you could use a company like Dating Sites Reviews to learn what dating sites are highest ranking and why, as well as what sites to avoid. Dating Sites Reviews includes actual user reviews of many different dating sites.
There are many online dating sites where you can meet like-minded individuals. Some such as christianmingle.com cater specifically to Christians, but other sites such as eharmony.com and match.com will match you with others who classify themselves as Christian.
An older woman can definitely use dating sites to meet new people. Dating sites are not just for dating, and you could meet lots of new friends, dating sites are not limited to just dating.
There are Mormon dating sites on the market. Ldssingles.com and mormondating.org are a couple of these sites where you can start your search.
I am not sure there are any men only dating sites. IF you mean gay/lesbian dating sites, all major dating websites have this option for you to choose on them.
There are dating sites exclusively for Latinos. The Latino dating sites include www.latinlovesearch.com/, www.latindate.net/ and www.latinamericancupid.com/.
There are a number of free dating sites for adults such as: pof.com, Okcupid.com, and sixsingles.com. There are also dating sites for teens such as tagged.com and meet me.com.
100 free dating sites can be found on the Internet. There are websites that list free dating sites and there are even YouTube videos that will list and review free sites.
only dating sites like yahoo because they can post their ads on Yahoo.com Google talk, AIM, MSN, and Myspace only like themselves.