Welcome! I'm gradually transferring over all of my sewing resources, so check back often for more.
For now, I have the following free .pdf files that you can download or print out:
Intro to Miniature Sewing
Whether you're totally new to sewing or a recent convert from the human stuff, check this out. It goes over how to pick out things like doll-friendly fabrics, short cuts, and stuff like tiny studs and buttons to add realism.
Action Figure Sizing & Resizing
This shows you how to adjust patterns for extra-large or weirdly shaped figures using an existing pattern instead of having to start from scratch.
There are also some Facebook communities I recommend for general knowledge and a place to show off your stuff
Doll Clothes Sewing with Requiem Art Designs
This is my group! If you sew anything from my patterns, you can post it here and maybe win stuff. You can also go through posts to see what other people have sewn up.
Sewing for 1/6 Scale
Focusing on dolls like Monster High and Barbie. A great place to share creations and ask questions if you're in a pinch. There are LOTS of dolly sewers here at all levels of ability, and very friendly!
No-Drama Doll Sewing & Creation Group
Focusing on bigger kid-shaped dolls like American Girl and Wellie Wisher. Also very friendly with lots of different sewing levels.