I've always been a huge advocate of #WritersSupportingWriters, and over the years (before querying, during querying, and just for fun), I've landed on a number of websites that helped me during the stage I was in.
Free Query Critiques
This might sound crazy, but I love looking at queries. Seriously. If you need a helpful eye, please subscribe to my website and fill out the contact form.
Features interviews on many of your favorite agents--new and seasoned.
A great place to track queries, query responses from agents (i.e, how long it takes to read a full, what their responses look like, other writer's experiences with said agent, ect.), and to find out where you're at in the queue!
Keep up on what projects agents and editors are buying! However, please note that this is a paid resource.
Melanin In YA
Your go-to source for all things Black in the Traditional, Young Adult realm.