I am trying to rent a home from someone that says he has half ownership to his grandmothers home. Before she passed away she put the title of the home in her grandson's name and in her second husband's name. The second husband died and his son got the other half of the title or property. The man's son is not interested in the property but won't release it to the other guy because of a dispute. The lady who passed, has a daughter that thinks the house belongs to her because she thinks that Louisiana Law gives the kids the parents property. This daughter is over the age of 24. How do I really know who owns the house and who I will be renting from? The house needs repairs and the daughter wants to fix it up and rent it to me, but the grandson says she has no right. What do I do? I am suppose to rent this property April 10, 2011.

... How do I really know who owns the house and who I will be renting from? ...

The only way to know for sure is if its decided in a court of law. And its not your place to ask a court to decide. So, unless you are comfortable with the prospect of getting thrown out midway through the lease, tell her thanks, but no thanks.

Go down to city hall in town and look up the property in the deeds office. The owner(s) of record are public information.
If there is a dispute going on or a lawsuit, it won't show there, however, so you could be asking for trouble by renting.
LA intestate (no will) law is extremely complicated so it's no wonder there is confusion. BUT the owner didn't die owning the house; she put it in 2 other names and took her name off entirely from what you say, so there is no dispute! The grandson and the heirs of the second husband are indeed the owners. IF the deed really was changed before she died, which it sounds like it was. Go find out.

And if you rent the property without the consent of ALL owners you are asking for trouble.

I'd walk away - unless ALL owners agree to rent to you you are going to be a pawn in their power struggle somewhere down the road.