Talk about a great resource for getting to know your characters! Not only do I use this site for understanding my own personality type (as well as my husband's!), but I love referring back to it when I need to know how one of my characters might respond to something.
If you're struggling to really dive deep into your characters' minds, take a look around this website. The super cute graphics are perfect for printing and keeping in your series bible or character worksheets.
I'm INFP--what personality type do you fall into?