Here's a pretty recent thread you can have a look through:
http://www.dakkadakka.com/dakkaforum/posts/list/671643.page But, if you're starting out to the point of not even knowing
BS and
WS, I'm not sure you should go in with another army. I doubt you're using the full weight of Dark Angels and to be entirely honest, Dark Angels are better than Blood Angels and Space Wolves. I'd say stick to your guns and expand one of the three wings more. Ravenwing is pretty friggin scary on the table.
But, to answer the questions,
BS is shooting skill,
WS is chance to hit in Assault. Both are pretty much going to be the same for all of the armies apart from Characters. That's how Marines work. Space Wolves do a Champions of Fenris Detachment to give certain units WS5 so you're hitting standard troops on 3+, but Blood Angels have the Baal Detachment to give them Initiative 5 on the charge so they're striking first most times before they can take damage back. Means less casualties most times IF you do things right.