A good mod for a new player is my Beowulf mod. It buffs MA Man by giving them a hero to start the game. It also removes old age from their crones, resulting in less micromanagement for new players.
Man is a good race to learn the game with as it has a good mix of infantry, cavalry, bowmen, and base evocation magic.
http://www.mediafire.com/?z1d4zsim9nx
just download it and extract it to dom III/mods folder. then when you start up the game, select preferences and enable the mod, then play ma man and you should give the AI a good battle!