How do I continue this position for black?

What is black's plan?

Try to move the mispositioned rook between King and Queen

Bb7!, putting pressure on e4  and aiming to White's castled king. Other moves to be considered in the future (the order would need deeper analysis): a5, Nd7

I woudn't do that while White's light-squared bishop is aiming at f7. 

Maybe ..c5 to make it a more sicilian setup. This does weaken your d5 and b5, but your a1 diagonal becomes stronger (+ you get b6). Then moves like Rb8 and Qb6 and Nd7 look good to me. Your main attacking would be on the queenside over the a1 diagonal and the b-line. Your a-pawn can push (maybe with the help of Bd7) to meddle with your opponents queenside structure.