First, you have to make your way off the island to queynos or freeport. You won't be able to get off of the island until you finish all of the quests that the ratonga near the archery range gives you, ending with killing the Orc Leader.
From here, I can only tell you about queynos, so I hope you're a good guy. Once you get to the island, you have a few sinple hallmark quests that end with your citizen quest. Just do what the journal tells you to, and you become a citizen of queynos.
Sorry if I'm being vague, but I'm not sure if you wanted specific details or a general idea. PS, all the experience that you gain in the time between not leveling and becoming a citizen still accumulates. When I got citizenship, I dinged two levels from the accumulated xp. W00T!!!
HTH