here ya go:

Trial Account Restrictions
The following restrictions are placed on all Trial Accounts:
  • A level cap of 20.
  • A maximum of 10 gold.
  • Trade skills are capped at 100 ranks.
  • Inability to trade via the auction house, mailbox, or player-to-player.
  • In-game chat channels will be unavailable.
  • A limit on the number of tells that can be sent.
  • Realms with login queues will give priority to customers with retail accounts.