A good one-stop resource that covers issues all across the gender spectrum in a clear and accessible manner.

This 90-page book, which was first published in 2013 and has since enjoyed multiple print runs, is an excellent, vibrantly illustrated primer on all things gender. Its explanations, exercises and diagrams are simple enough for all ages to understand. It is available via e-book, but many pages are freely accessible on the website.

A YouTube channel for LGBTQIA kids with videos on growing up queer, gender expression, consent, being a good ally, the spectrum of gender identities and sexual orientations, class, race, disability, mental health and privilege, among other things.

Asia Pacific Transgender Network curated this 24-page factsheet for trans youth, centred on sex and sexuality. It covers frequently used terminology, tips for safe and pleasurable sex as well as reproductive health and fertility choices.

This website compiles answers (sometimes serious, sometimes funny and personal) to questions posed by LGBTQ kids on topics ranging from coming out to bullying to navigating religious families.

The Trevor Project provides crisis intervention and suicide prevention to LGBTQ youth in the U.S. Its Trevor Support Center is a collected FAQ for LGBTQ youth and allies, touching on topics like crushes and school situations, asexuality and bisexuality, mental health and self-harm. It also features "Coming Out", a short handbook for young people deciding whether and how to come out, both in terms of gender identity and sexual orientation—with tips on factors like timing, location and safety.

The Asexuality Archive is a fantastically thorough collection of information about what is sometimes called a "fourth orientation". Browse sections entitled "Asexuality 101", "Asexuality in the World", "An Asexual's Guide to...", "Asexual Life", "Activism" and even "An Exploration of Doubts", for those who aren't 100% sure about being ace. (Some of the materials may be advanced and aimed at older users.)