I am in the process of creating a 1st level encounter now. I am thinking of having the one of the character's mentors send the characters to go clean out some dire rats at one of his associates's farms. On the way back I am going to have a small gang of human warriors associated with one of mentor's enemies attack the party. I hope to set up a recurring enemy, inspire an investigation and give a little depth to my home brewed campaign. I figure the antagonist will belong to a cult or something... The main point is it should get their interests up enough to create a climate of lasting trouble