What's the best resource for pallets to make easy pallet furniture?

grocery stores

depends.industrial area have them in there back yards for free,research craigs list, drive around the back of stores, note not all have them for free

Any store that gets items shipped on them. Grocery stores, liquor stores, hardware stores. Check out in the back by the dumpsters and shipping docks. Very few free in my area, they all know people want them so now they charge for them. Also check freecycle.org and Craig's list. Nextdoor.com is another good place too.

https://www.1001pallets.com/

Probably a warehouse that uses the pallets with their shipments. Or the company receiving the products

construction sites, ask the superintendent and they might give you more than you can ever use, I've thrown away thousands

Thank you!