the rough list you have there is pretty good. I would suggest you swap round the unit sizes for the warriors and xbowmen. I'd take 10 xbows and 18 spearmen.
other than that its a great base to start from, the lord on black dragon is a beast, hatred on a dragon is extremely nasty. 2 sorceress should be able to keep you reasonably defended from the nastiest of enemy magic while dishing it out in return. corsairs are a reasonable troop choice as well, 2 hand weapons is best and i like the frenzy banner on them to maximise their output, hatred + frenzy = win.....until your opp baits you away but hell there going to have other things to worry about.
black guard are awesome, the bag of hag graef makes them one of the best elites in warhammer. harpies for re-direct, charge bait, warmachine hunting. coldones knights are a good hammerblow unit which are reasonable tough...for elves there tough. and 2 bolt throwers and hydra keeps your options open and means you can hang back if you need to and take a few wounds of enemy big stuff[like there black dragons ;)].
the hydra is the hardest thing point for point in warhammer in my opinion.
for someone new this list is impressive, and looks fairly close to what alot of competative darkelves players are using at the gt this year.