Hi and welcome to DC
I cook them for about an hour at 350°F. That will soften the peppers nicely.
Alright that sounds right. Do I cook the rice and the pepper seperate and then stuff the pepper after they both cook? Or do I cook the rice, stuff the uncooked peper, and then cook them? That's the only thing I'm confused on.
If cooking rice in advance and letting it go cold be very careful.This is one of those recipes that was invented to use up leftovers. Cook the rice first (or make extra one night, and them make the stuffed peppers another night), then combine with the other ingredients, stuff the raw peppers and bake them.
Here's a good basic recipe; you can sub ingredients as you like: Betty Crocker Stuffed Peppers