I pick up tools and such from Track of the Wolf - mainspring vise, jags, etc.
Various Bahco files from Kibler and Amazon.
Dovetail file from Brownells (two safe sides, one fine).
Tried & True varnish oil from Amazon.
Iron Nitrate from Kibler.
Tannic acid powder from Amazon.
Jax brown from Kibler (used on the brass).
Oxpho blue from Brownells (used in the steel).
Bulk scotchbright pads from Amazon.
Rolls of adhesive-backed 120, 220, and 320 from Amazon.
Rubber sanding blocks of various shapes from Amazon (a variety of shapes in a package for around $10).
Sanding stick things from Amazon (set of plastic pencil like contraptions that use thin sanding belts for getting into tight spots).
I’ll echo the recommendations to watch Jim’s YouTube videos. Then watch them again. Also listen. He slips in a lot of good tips that might be mistaken as an off comment or random jibber jabber.
Don’t just watch the Woodsrunner videos. He hits on various things in his Colonial and SMR videos that he skips in the Woodrunner series, and he’s got several more focused videos (sanding, finishing, etc). I followed them all pretty closely and ended up with something I’m very happy with.