Something you need to keep in mind, especially in smaller points games, is that with the new book, all undead units must be within 6" of a vampire or 12" of your general in order to make march moves. Keeping your general safe is always a top priority for VC, but in smaller battles its even more essential, since you may only have 1 other vampire which then would have to keep your whole army in line.
In 2000pts, the amount of units you field is even larger, and if you want to have an army that does more than just huddle together and receive a charge you'll want a Vampire General, Hero and maybe even another Hero or Vampire model (Varghulf, Black Coach, and Blood Knights are all Vampires and support march moves), like a Varghulf paired with a flanking unit of Black Knights.
Instead of writing a tactics article, I'll link you to one:
http://www.games-workshop.com/gws/content/article.jsp?community=&catId=cat50038&categoryId=400027&aId=2300007 .
As an undead general you must know your greatest advantages: Magic and Fear. Enemy shooting and combat can deal a lot of damage to your basic troops, as even skeletons will have a hard time beating most enemy Core choices. But since all Vampire and Necromancers begin with knowing Invocation of Nehek, even if you give them no magic upgrades, your heroes can raise your units back to starting strength - or beyond, if a character has the accompanying Bloodline Power. In this way a unit of 20 skeletons with HW/Shield, Standard, and perhaps a Vampire Hero as some combat support can shrug off losses and use its static Combat Resolution to win a combat, and possibly auto-break the enemy if they outnumber them due to fear.
Your other key spell is Vanhel's Danse Macabre, and it's reason enough to squeeze in some Necromancers or giving your lord Forbidden Lore. An extra move/charge opportunity is huge and this spell will literally win you the game, so expect your opponents to be expecting it.
Core troops seem pretty bad, and for the most part they are, but that's in terms of killing stuff. Zombies are dirt cheap but won't kill a THING and can stall enemy units for multiple turns, since they will never run from combat even in the face of horrendous casualties. Skeletons, at twice the points, are the mainstay unit of the VC, with an OK save, static combat res. from ranks + standard, the ability to take magic standards and be raised by Invocation. So take some!
(Ghouls vs. Skeletons - The debate over which core unit should be taken over the other still rages. They're both effective and armies succeed with either, so just know that Ghouls are more offensive/capable of causing kills with 2 poison attacks each, while Skellies benefit from command options, magic standards or spears.)
Grave Guard (GG) are your best infantry, as even the basic outfit of HW/shield gives them a good save in cc. Some players use the Drakenhof Banner to give Regeneration, but this is both very common, expensive, and predictable. With decent magic support they will have the same survival rate, and adding something like a Wight King BSB w/Sword of Kings for challenges and/or giving the unit the Banner of the Barrows so all the Guard (and the WK) get +1 to hit. GG will probably form the center of your battle line, and they make great anvils to keep the enemy in place while you get a flanking charge.
Overall, take some good units of skellies that can take some punishment, maybe a unit of zombies to hold one flank, or some grave guard to form the battle line. Keep good Vampire coverage with a General in the center and other vampires where you need them, even for your flanking elements. Your Lord can be good at combat or magic, but risking him in combat can be disastrous, and he can be the magical core of your force casting Invocation 5 or so times each turn to keep your units going strong. Cast Vanhel's Danse to get those critical charges or to make your units strike first/get bonuses to hit and swing things your way. You can challenge characters and monsters with Skeleton/GG champions and then resurrect the champion back the next turn, causing endless headaches. With a solid core of troops backed up by some good magic, a combat character or two, and some hard-hitting choices, you'll learn to get better and see what parts of your army really do what. There's no need for you to use cheesy lists or un-fluffy deathstar units, and doing that nearly always makes games less satisfying. Keep at it and you'll be fine. Unless you're playing to win a tourney, it's always more fun to have a close game with a nice player.
