I'm far from anyone to be giving game advice but I find these channels are somewhat interesting on a rainy day. The first channel is by zzirGrizz. He is (apparently) a good, popular player. He likes using snipers, so if you want to learn by a "monkey see, monkey do" tactic, you might want to give his channel a try. He also has some nice tutorials and a few rather humorous clips.
The second channel is from XboxAhoy. He is doing an in depth guide for each of the guns currently, and I must say his voice makes me fall in love with each weapon. I used to think the Enfield was such a turd, now I seem to use it a lot. Go figure. Intertwining history and game statistics, it's definitely the history channel of Black Ops.
Anyhow, that's all for this post. I'd just like to note I don't get commissions from this, and neither of these are my channels. Enjoy.