Cameroon international Song completed his switch to the Catalan club for a fee in the region of £15m yesterday afternoon.
That move has seen him reunited with Spanish midfielder Fabregas, who he has been staying with since arriving in Barcelona.
"I know Cesc very well, I slept at his house [on Sunday]. He's a very good friend of mine, he will help me to integrate," Song told reporters.
Song is expected to make his debut during Thursday's Super Cup encounter against Real Madrid.