Deliver Sven's Letter to Camilla

Optional Quest:

Speak to Sven, the bard at the Sleeping Giant Inn in Riverwood. Ask him about "you and Faendal like the same girl, right?"

He will ask you to deliver a false letter to Camilla, full of nasty things, and to say that it was Faendal. At this point, you have two choices.

Help Faendal:

Tell Faendal about Sven's plan. He will then give you another false letter, this one supposedly from Sven. Then, go find Camilla, who works at Riverwood Traders. Speak to her. You have two choices. If you lie and tell her the letter is from Sven, she will become mad and tell you to tell Sven to never speak to her again. Return to Faendal. If he is not at his house, he may be near the lumbermill. He will reward you with 25 gold (at level 4)

Help Sven:

Your second choice is to tell her that it is from Sven. She will ask you to speak to Sven and tell him what you did. Sven will also reward you with 25 gold (at level 4)

If you help either man, they will now follow you and offer help. If you help Sven, only Sven will follow you. If you help Faendal, only he will follow you.