There are some excellent resources available through national organizations, here are a few to get you started.
The Trevor Project is a national organization with the mission to end suicide among lesbian, gay, bisexual, transgender, queer and questioning young people. Through crisis services, advocacy, research, peer support, and education/public awareness they strive to achieve this goal.
PFLAG is the nation's largest organization dedicated to supporting, educating, and advocating for LGBTQ+ people and those who love them.
Native Youth Sexual Health Network (NYSHN) is a grassroots network of indigenous youth and intergenerational relatives that works across issues around reproductive health, rights, and justice.
The National LGBTQ Task Force builds power, takes action, and creates change to achieve freedom, justice, and equity for lesbian, gay, bisexual, transgender, and queer people. As the progressive voices of the LGBTQ movement and the LGBTQ voice of the progressive movement, the National LGBTQ Task Force organizes people and money in pursuit of liberation for all.
GLAAD (Gay & Lesbian Alliance Against Defamation) is a non-profit organization focused on LGBTQ advocacy and cultural change. Their mission is to ensure fair, accurate, and inclusive representation and creating national and local programs that advance LGBTQ acceptance.
Human Rights Campaign is the largest movement for LGBTQ equality in the United States. Their mission is to inspire and engage individuals and communities in order to end discrimination against LGBTQ people.
InterACT Advocates for Intersex Youth is an organization that uses innovative legal and other strategies (fostering youth advocates and raising awareness via social media), to advocate for the human rights of children born with intersex traits.
Horizons is a community foundation of, by, and for LGBTQ people. They are committed to centering equity and inclusion in every aspect of the foundation through grantmaking and programs, their board and staff, their policies and practices, how they invest, and their public roles.
GLSEN stands for Gay, Lesbian & Straight Education Network. They are an American education network founded by a group of teachers in 1990. GLSEN works every day "to ensure that LGBTQ students are able to learn and grow in a school environment free from bullying and harassment".
The GSA Network has plenty of resources that can support you in starting a GSA near you.
Healthy Native Youth is an organization that provides health promotion curricula and resources for American Indian and Alaska Native Youth. The curricula housed on their website promote positive youth development, embrace cultural teachings, and demonstrate evidence of effectiveness. Their site is designed for tribal health educators, teachers, and parents.
All descriptions are adapted from or provided by publishers.