Eureka

• WWizards of the Coast2004-10-04
  Official Ruling
  In a game of N players, the process ends when all N players in sequence (starting with you) choose not to put a card onto the battlefield. It doesn’t end the first time a player chooses not to put a card onto the battlefield. If a player chooses not to put a card onto the battlefield but the process continues, that player may put a card onto the battlefield the next time the process gets around to them.
• WWizards of the Coast2004-10-04
  Official Ruling
  If the card has an X in its mana cost, treat X as zero.
• WWizards of the Coast2004-10-04
  Official Ruling
  The cards are put onto the battlefield and will not trigger effects which trigger on such cards being “cast” or “played”.
• WWizards of the Coast2006-10-15
  Official Ruling
  Anything that triggers during the resolution of this will wait to be put on the stack until everything is put onto the battlefield and resolution is complete. The player whose turn it is will put all of their triggered abilities on the stack in any order, then each other player in turn order will do the same. (The last ability put on the stack will be the first one that resolves.)
• WWizards of the Coast2007-09-16
  Official Ruling
  A “permanent card” is a card that would be a permanent once it’s on the battlefield. Specifically, it’s an artifact, creature, enchantment, land, or planeswalker card.

Rulings via Scryfall