Just to confirm, when you say that you've done some reading, can we assume that you've read
all three handbooks linked to in the handbooks section? I don't mean to sound snarky; they do contradict each other fairly often and I can understand wanting some clarification. We just need to know where you're coming from.
What do you want to achieve with this character? Minion-Master, Ultimate Debuffer, Fearbot, Goofy Sidekick, or something completely different?
What is the rest of your group like? Do they tend to optimise?
Do you know what type of campaign you're going into? Will you be going up against clerics and paladins often? Is it ok to play an evil character, or will this cause problems with the rest of the party? Is it ok to play an undead character, or will you be turned within the first 5 minutes of the first session?
If you don't want to or can't answer the above, that's fine - but the more information you give us, the more we can help you.
[edit]: Also, how is your DM handling EXP? Becoming a Necropolitan is a very attractive option, but you'll want to clarify exactly what the loss of a level (NOT LA) means at character creation.