New to Wine making

I'm almost finished making my first batch of Blackberry wine, I've racked it twice and its just about stopped bubbling, I'm excited. One question about this batch, I've read I can add sugar to adjust the sweetness before bottling if I do this do I use camden tablets to stop any futher fermation or do I use something else?
Question #2 I'm starting my next batch of Blacberry wine, while searching for other recipes I noticed several recipes that called for raisins (small amount) to be added to the berry mixture in the fermentation bucket....What purpose do the Raisins serve?

 

Raisins give a weak wine more body. And campden alone isn't enough to stop fermentation.