Ok, everyone... We are building a good Necromancer, not some sissy one... First, Specialize in Necromancy, take Tattoo Focus(Necromancy) and Empower Spell (of no use to begin with, but a good start) and you get Scribe Scroll as a bonus at first level, play a human, give up illusion and enchantment (your not going to hide what you are). Take 5 levels as a Necromancer, taking Spell Focus (Necromancy) at 3rd and Maxamize Spell as bonus 5th... You now qualify for the Red Wizard PrC... When taking Red Wizard, forfeit Conjuration, it will limit you a bit, but it does leave you with the big hitting schools of Evocation and Transmutation... And you can cast any conjuration up to 3rd level which gives you the all important Mage Armor and Melf's Acid Arrow... Continue progressing and at 6th or 9th, take Leadership and the other feat, save for Greater Spell Focus (Necromancy)... I personally would wait till 9th for Leadership... Now you have a cohort as you advance to 10th Character level, making you 5th Level Necromancer/5th Level Red Wizard and you now have Circle leader special ability, that right, you can channel your cohorts (who of course has Tattoo focus) spell levels into your Necro to enhance your spell casting ability (this is where your empower and maximize comes in handy)... So as a 10th level char, your cohort could be as high as 8th, giving him 4th level spells (straight class him as a wizard or let him follow the Red Wizard PrC as well), when you do the circle, that is 4 phantom spell levels that you can use to maximize, empower, increase caster level, etc (and just think if you have other followers that cast spells, you can give them tattoo focus to give you more spell levels)... Now you being 10th level, gives you access to up to 5th level spells... So, exactly how nasty is that Maximized enervation - take away 4 levels... Ohhh, empowered Enervation - take away 1d4 x 1.5 levels... and you could easily cast that twice, just with the bonus spell levels from one cohort... Don't forget Enervation does not get a Saving Throw either... There are several other Necromantic spells that don't get saving throws out there... Ray of Enfeeblement, Maximized is a 4th level spell, no save, and would do 11 points of strength drain, use your bonus spell levels and empower it now to do 16 points of strength drain... that is -8 to anyones attack and damage...
Just remember, necromancers don't have to be all about undead. Yes, they can be a decent force to be reckoned with - however, what 7th level fighter can't chop it's way through some of the best undead? All they are is cannon fodder, so you can bring your big spells to bay...