That depends on what focus you want the speech to take. I could fill up 5-7 min defining terms easily...but that type of lecture would likely put people to sleep.
I'm curious why do you want to do your speech on trans individuals? What message do you want you're audience to take away from the presentation? Once you know those two points the rest will likely fall into place.
Some resources I'm using as I prep for a class I'm teaching include:
The Human Rights Campaign's page on Transgender Issues
http://www.hrc.org/issues/transgender WPATH's Standards of Care
http://www.wpath.org/documents/Standards%20of%20Care%20V7%20-%202011%20WPATH.pdf National Center for Transgender Equality
http://www.transequality.org/ Hudson's FTM Resource Guide
http://www.ftmguide.org/\ Transgender Day of Remembrance
http://www.transgenderdor.org/ Those should help get you started. If you need more information, to pull from peer reviewed sources, or have a hard time narrowing your focus I'd suggesting talking to a librarian. If they follow the ethical standards of the field your questions will be confidential and they are more likely to be able to provide you with a specific direction, rather than semi-random links by a library student who does research on the side ;-).
For an example of how knowing your goals for a presentation can help it come together I'll use the 1.5 hr class I'm doing for Trangender Day of Remembrance in November. What I want them to take away from the class is empathy for the trans community, knowledge of some gender variants (breaking gender binary) and a realization of the importance of gender and how gender bias can cause harm.
To do this I'm having guests teach gendered activities for about a half hour. During this time those who are male identified (by their own choice) will be asked to go with a local professor to learn to knit, the women (again based on self-identification) will be sent outside with my friend to learn the basics of swordplay. I'm debating asking my presenters to use the pronouns associated with their activity to reinforce the impact of being gendered. This activity should breed empathy.
After that I'll bring them in for discussion. This is to let them process the experience, consider how difficult it would be to constantly be forced into activities that don't fit their view of themselves and possibly even look at why those activities are gendered the way they are. During this discussion I'll introduce genders & sexes that defy a binary view of gender/sex such as trans, gender queer, intersex, intergender and androgyny. Hopefully this will elaborate on the empathy and provide a correlation to situations where individuals are forced into roles associated with a gender that is wrong for them.
The third section is my personal soapbox. I'll use my transition as an example of the complexity of the process of transitioning in the medical and legal world. I'll be in my eight month of transition at that point and very close to fully transitioned legally, so I know that my path is one of the fast ones. This is to demonstrate the costs of a gendered legal system on an individual who has the resources to jump through all the hoops.
For the final piece I plan to introduce them to the individuals who were murdered in the past year for their gender/sex. This is done both to remember and honor the fallen and show the ultimate cost of a biased society.
I hope this helps. If you have further questions, please feel free to ask away. I hope your finger heals. Best of luck on your paper dude!
