Helpful Resources

Breed Documentation:

The NAMHSA breed list, Lesli's breed list and Wikipedia are good starting points for breed assignment
Websites for breed-specific registries - search for the actual breed standard
Good breed reference guide (I recommend the following):

International Encyclopedia of Horse Breeds by Bonnie Hendricks (ISBN: 978-0-8061-3884-8)
The Official Horse Breeds Standards Guide by Fran Lynghaug (ISBN: 978-0-7603-3804-9)
Horses of the World by Élise Rousseu (ISBN: 978-0-691-16720-6)

Model Horse Documentation Creation Facebook group https://www.facebook.com/groups/303835936077938

Collectability:

Model Horse Collectability https://modelhorsecollectibility.blogspot.com/
Breyer History Diva https://breyerhistorydiva.blogspot.com/
Identify Your Breyer https://www.identifyyourbreyer.com/
Model Horse History http://www.modelhorsehistory.com/
Many Mini Hooves (Stablemates specific) https://manyminihooves.blogspot.com/
Breyer Value Guide https://www.breyervalueguide.com/ * Membership required
Stone Horse Ref https://www.stonehorseref.com/ * Membership required
Breyer Horse Ref https://www.breyerhorseref.com/index.php/ * Membership preferred
Just About Horses magazine back issues
Felicia Browell’s Breyer Horse Collectors Guide (any edition)
Nancy Young’s Breyer Molds and Models
Model Horse Gallery https://www.modelhorse.gallery/index.html
My Shelf Life https://www.myshelflife.net/my-blog
The Model Horse History Project https://modelhorsehistory.blogspot.com/

Finding Live Shows:

Macie's Model Horse Musings