What are (if any) the laws surrounding selling original artwork?

Let me explain:
I am going to assist in selling thousands of paintings (none well-known) all done by local artists. They be inherited by this man through his deceased friends estate. The friends had bought them over the years, hoping they would be worth something someday. There are roughly 10,000 painting. I am going to help this man sell them via craigslist, yard sale, etc. I want to know if there are any laws I might be oblivious of, i.e. profit rights to the artists...or if they lost rights when the piece was sold originally. I propose, people sell paintings on craglist adjectives the time...but since I am selling such a huge quantity, I want to make sure theres nothing permitted I might be overlooking.
I hope I explained that well enough. I appreciate your input!
There aren't any rights for that. He sold his art without an agreement contract dictum something like "I get 20% of the profit of so and so painting". They belong to the owner and he can do whatever he like with them...But 10,000 paintings is a lot! They can't adjectives be from one person, can they? If the artist is still alive, it would be courtesy to ask if you could sell his art, but not a law.

Best of Luck!
As long as you've got proof of ownership you have nothing to verbs about. The painter has rights to what they painted, but this means you couldn't fashion a duplicate of the painting. Think of it like a photo - you go and hold your pictures taken, the photographer legally owns the rights to the picture, but will sell you a copy for a price. You may then go that photo to anyone you want, BUT you could NOT make a copy of it.

Since your just selling the copy onward there's no problems, left someone claiming it was stolen from them. However if they're all low-end, no-name paintings later I wouldn't worry about that since most aren't going to be concerned looking for them.
I am an estate broker and an antique dealer. The merely thing you need to make sure is that none of those painting are supposed to go to legal heirs. If to be precise all clear, you should have no other problems.

Artists rights only apply to reproduction of the sculpture. The artist made his profit when it was sold, so you don't have to worry almost that.

Have you thought of holding a local auction? I personally have found that local art (unless the painter was immensely well known) go for much more in the nouns they are painted than say on Craigslist or eBay.


edit: I forgot to add that you can find out roughly the heirs by requesting a copy of the deceased's will which would have been file in the local government office within which the previous owner died.
as long as you enjoy ownership then there is no problem here. You probably have some painting that are worth more than you realize. But, once the artist sells painting, he no longer has any legitimate claim to them.