The resources here have really helped me when it comes to developing characters and understanding various types of narratives.
To be honest, most of these links pertain to the scriptwriting process. Writing for games is possibly different from writing for film, television, and literature, but its valuable information nonetheless and can be applied to rpg maker projects.

Final Boss Blues is a legit site that offers great tips for the PC Makers. Check out the podcast, it covers endings, dialogue, etc.

http://finalbossblues.com/

Narrative Breakdown is exactly what it sounds like. The host and co-host breakdown various types of narratives in fiction. Highly recommend checking out their episodes on creating compelling characters.

http://www.narrativebreakdown.com/


Just take a look at that sidebar. Cockeyed Caravan is chock-full of good stuff regarding plot and characters. There's a heavy amount of reading here, but I recommend the "HOW TO CREATE A COMPELLING CHARACTER" section

http://cockeyedcaravan.blogspot.com/

Good stuff all around.