I agree with Kurald; the class features suck. Badly. The Corrupt keyword is essentially useless as well; never use it, and doubly never use it in battle. Looking at the powers, most of them seem underwhelming, too. Unfortunately, there's no real secondary stat for the class - Int gives a bonus to damage on some attacks, but nothing else, and Con does... well, nothing that it doesn't for everyone, but you're not going to be using your surges for the class's abilities (because they suck). You should thus focus your attributes on Charisma and Dexterity, because Int's usefulness is minimal and your Dex boosts your initiative.

The best at-will power is obviously Skeletal Minion, which, after a standard action to create it, gives you an at-will minor-action attack once per round. Poisonous Burst sucks, starting weak and getting even weaker as you level; no damage roll = no implement, feat, or... basically any other damage bonus, so it just deals straight Cha damage +the ongoing at all levels. ~7 damage at level 1 is OK, but ~10 at level 30 isn't, and that's how it's gonna scale. Scythe of Dread is boring, but practical enough. Withering Strike is much the same.

You're going to want items that change your damage type. The class is a one-trick pony with necrotic damage, so any undead enemies or others with necrotic resistance will basically completely rape you unless you've got a damage-type replacer. That severely limits your options for magic weapons; if it doesn't let you change the damage type of your attacks, you don't take it. Armor should be hide, since you should (as mentioned above) have a good Dex and thus should have as good or better AC with hide than with chain or plate. Other items involve things that will boost your minions, as even if the only one you've got is the Skeletal Minion that's so outrageously useful that you might as well buff it and it looks like other minion powers are among the strongest of their levels, things to ignore resistances, and things to boost your own survivability as normal.

Feats... Well, things that give bonuses to your minions' attack and damage rolls are going to be the best, followed by defensive boosters (lower priority than for most summoners, as you've got an at-will one). Again, and I cannot stress this enough, you're not going to be using healing surges to power this class's powers or abilities (because they suck), so things that grant bonus surges aren't any better than normal.

Powers to especially avoid that I noticed while going through to check whether there were any healing surge-based powers that were actually decent include Darkcinder Blast, Frost Nova, Dreadful Rage, and Necrotic Nova. These powers drain a healing surge from you as part of their Hit line, and have multiple targets. For every target you hit you lose a healing surge. Dreadful Rage is a close burst 20; use it and every single one of your remaining surges went into the toilet. These are so incredibly terribad that I must imagine that this ThePlaneswalker person must either never have played 4e or made grievous mistakes when he was creating this document.

Healing surge-based powers that are decent-to-good include Vampiric Regeneration (allows 1 target to heal from 1 hit point to full for 1 healing surge during a short rest) and Transfer Life (transfers a surge to an ally and gives them a tiny amount of surgeless healing). Transfer Life probably shouldn't be taken, however, as Shade Form on the same level is better (lets you heal from 1 hit point to full during a short rest without needing to spend a surge).