Don't know how it was in 'em ol' days, but today the Tomb Kings are probably one of the more stable armies in
WHFB. Their armybook haven't been updated in a while, but it differs from other "nerfed" armies in that it actually still works on a competitive level. The spell casting is as it always has been (to my knowledge) that the wizards don't generate power dice but instead cast the incantation automatically with a power level equal to
2d6 in the case of a Priest and
3d6 in case of a High Priest. Simply said, there is no army (except perhaps High Elves and Tzeentch Daemons with Kairos Fateweaver) that rival Tomb Kings in the magic phase. As for their power on the battlefield, I refer to my own Tomb Guards and Ushabtis who haven't suffered one casualty since I started with them and have taken down several regiments and heroes (even a lord or two too). My recommendations is that you take plenty of Chariots, some heavy cavalry, a large block of regular warriors with spears and shields, two groups รก 20 archers, a 20 strong Tomb Guard, 5 strong Ushabti and a Bone Giant. I haven't lost many games with that combination. A Tomb King/High Priest with backup of two Priests and a Icon Bearer ensures that you will dominate the Magic Phase and have enough characters to move along with your army so that they don't get bogged down/die too quickly. Of course you should experiment around and not just take my suggestion for granted, my playing style is passive-defensive in combat with a few hard hitting units and fall-in flank of fast chariots, all supported by a hail of arrows and dominating magic. If you ever get some points over (that is, about 165 points) PAY UP for a Casket of Souls and place in in clear view of your enemies. With this however you should consider having some Tomb Scorpions to burrow up under the enemy artillery, you don't want to lose that casket to a cannon ball.
That's all the juice I have for you. Unless someone else have something to come with... *hint hint*
EDIT: As for putting the Tomb King in a chariot: Yes, by all means, but hold him in the background, you don't want to lose him, but instead keep him as support. If you feel extra sadistic you can throw in a Prince with Collar of Shapesh in the Warrior block and you will get a hero which possibly won't die until you are out of Warriors (and anything else within 4"). Add to this the Curse special rule and you can challenge any enemy character that irritates you, and even if you lose, you might actually kill the bastard.
A CHariot of fire is a good compliment to any Tomb King which you wish to get into the fray, add a Golden Eye of Rah-Nutt and BANG,
D6+1 inpact hit which counts as magical and fire and a 5+ Ward save for the chariot. If you decide to put your Tomb King on the ground with your Tomb Guard, give him a Blade of Setep to take away normal armour saves from the enemy. Additionally, any magical armour which is struck by this weapon automatically save, but will be destroyed for the rest og the battle (so feel free to challenge anyone =p). The cheap Shield of Ptra (15pts) will be a good counter to any challenge mongerer. If it successfully saves, it brings down the
WS of any unit in base contact to 1 for the rest of the combat round.
I will probably remember more as time goes along, so keep checking back... =p