You are talking about two things: permission and schema (same as owner in SQL 2000).
grant statement just Grant the permissions of the commands.
e.g. Grant create procedure to User1
Whether User1 can create procedures owened by other users is determined by its database roles or server roles. If User1 is a member of sysadmin server role or db_owner database role, he can create procedures owned by either dbo or user1. If he is not a member of the roles, he can only create procedures owned by himself.