not a resource per se, but i recommend getting a pair of machinist's indicator holders. they make the best helping hands i've ever used when retrofitted with alligator clips, because once tightened they have zero springback so they permit holding parts far more precisely than the usual blue plastic affair. i have a pair of these (https://a.co/d/0dyGqDEh) clockwise tools ones and they're fine, but there are definitely cheaper ones out there that'll work.