Miley Stewart looks like a regular girl-next-door, but she's got a big secret. When the lights go down, Miley is the famous teen pop sensation Hannah Montana This boxed set is packed with the first four Hannah Montana junior novels based on the hit Disney Channel show, including Keeping Secrets, Face-off, Super Sneak, and Truth or Dare. Book 1 - Keeping Secrets ISBN #1423102215Book 2 - Face Off ISBN #1423102223Book 3 - Super Sneak ISBN #1423102762Book 4 - Truth or Dare ISBN #1423102770
Various is the correct author for any book with multiple unknown authors, and is acceptable for books with multiple known authors, especially if not all are known or the list is very long (over 50).
If an editor is known, however, Various is not necessary. List the name of the editor as the primary author (with role "editor"). Contributing authors' names follow it.
Note: WorldCat is an excellent resource for finding author information and contents of anthologies.