I thought the wand stuff was ok to follow. But I could be wrong
Here is how I understood it.
In order to get the elder wand you have to "beat" the owner out of it. The wand will only fully work for the new user if they directly disarm, stun or kill the previous user. Also the wand has no true owner. It only responds to power and will do no real harm to its current owner.
Dumbledore had the wand from his duel with Grindelwald. Draco Malfoy got the drop on Dumbledore and disarmed him but Malfoy didn't kill Dumbledore. So technically the wand belonged to Malfoy when Dumbledore died. Harry "beat" Malfoy in the room of requirement so the wand belonged to Harry. Dumbledore hoped by having Snape kill him Snape would end up the owner of the wand. But since Malfoy disarmed Dumbledore first that did not happen. Voldemort got the wand from Dumbledore's grave. He thought it belonged to Snape. When Voldemort killed Snape he thought he would be the owner of the wand. Since the wand will not harm its real owner, when Voldemort tried to kill Harry with it...it turned the spell on Voldemort. So Harry is the owner of the elder wand until he dies naturally or is "beat". Dumbledore believes that natural death of the owner of the wand will end the power of the wand.
That is my sorta short take on it. Obviously if you read the books you know it is a much longer story than that
I am addicted to those books. I read all of them in about three weeks. I couldn't put them down. I have pre-ordered the beetle bard book already.
I am interested to see what they do with the last two movies. There is a lot of stuff in those two books. The movies are going to have to be really long or they are going to have to assume that you read the book like they did with The Order of the Phoenix. There was a lot left out of that movie.