What Amboadine said is a very strong point. The general rules are going to be revised completely, and the 'rumours' say that big changes are coming, including several models simply not "being there" in the new rule set. However the DE army book is rather "young" at little over a year, so I have this trust that our units will make it though
The warhost is generally not "competitive", at least in my opinion and based on my experiences and playstyle - which is again ehavily influenced by the local meta
it would help us in advising you, if you say how much you know of models, units and stats... Do you for example know what armor saves, ward saves and T / W means, and so on
The power units in our army book is, listed by their (in my personal opinion) power:
1. Pegasus masters
2. Warlocks
3. (mounted optional) supreme sorceress / mounted dreadlord (pegasus optional but very very good)
4. Bolt Throwers
5. Dark Riders
These five/six choices alone can build you a power army to be reckoned with. It will be difficult to play at first since the movement phase is both the most difficult but also the most critical phase, but once learned, the rewards will be great.
Optional support choices include shades and harpies.
Example rough 2000 point list if I where to build an ultra competitive balls to the wall list:
Pegasus dreadlord with various good magic items, popular loadouts are cloak of twilight + dawnstone OR ogre blade, other tricksters shard and talisman of preservation.
http://www.games-workshop.com/en-DK/Bre ... sus-Knight <-- buy this guy and a cold one knight bit from a bit seller or ebay. You can buy dark pegasus wings on the DE section if you want them to look more badass, but the standard bret wings work just fine.
Lvl 4 on steed (she may be abit expensive but has so much more mileage than a lvl 4 on foot!). Buy the lvl 4 from the dragon kit as bits + a dark steed from the chariot kit as bits if you can. Alternatively buy the mounted high elf mage and say he's a turncoat
Pegaus master BSB. Again, same procedure as for the dreadlord. Try to get a hold of a pretty flag and paint it super well, the battle standard should be the pride of your army
popular loadouts are: talisman of preservation + charmed shield (in conjuction with a cloak lord) or cloak of twilight (in conjunction with the ToP + OTS lord).
Fill your core with dark rider units. Units of 5 and maybe a single unit of 10 in which your sorceress could go in an emergency. Dark riders are
so much better than all other core units that you simply cannot compare. However, if you're going to play in a comped environment, many restriction sets limit dark riders for this very reason
if so, add smaller units of darkshards or witch elves. In general, dont bother with standard warriors in this edition!
For your special choices, its a no brainer. 4 bolt throwers, go go.
For your rare, look to one unit of 10 warlocks (with a mounted lvl 4) or two units of 5 (with a lvl 4 on foot). Popular lore choices for your lvl 4 is death (since warlocks come with built in magic missiles) or dark (for many many magic missiles).
This is a reasonably cost efficient starter list. I cant put a precise price on it but check the units out and see if you can manage it