black white attempt. help appreciated

It all depends on what you are trying to accomplish with this deck. Is it a standard deck? Will it be just used for casual or will it be semi-competitive?
I see there is a bit of a life gain/life loss theme here but some of your cards are extremely highly costed like sip of hemlock and corrupt.
Consider using some lower costed killing spells like doom blade, Ultimate Price, Bile Blight or hero's downfall as they will be much more help at 2-3 cmc than sip of hemlock's 6 cost. Also Tithe Drinker with extort and lifelink fits well with your deck. Blood Baron of Vizkopa is THE BW card. Very Very strong.
If you want a bit of hand hate you can add Duress as a cheap option as well as Sin Collector.
That's about all I can help you with given the cards in your inventory/easy to find cards. The typical BW deck looks something like this: http://www.mtgdecks.net/decks/view/66299

Also It's much easier for people to see everything if you put this into a deck and then a link to it, not just typed out.

Hope this helps