basically the host of the game loads you up into Llamaserver(the server in which most MP games in Dominions are hosted on), all you have to do is send in your pretender(after all players joined and game closed by the host) and than send each turn you play. to save you further questions, you need to email your pretender to
pretenders@llamaserver.net and your turns to turns.llamaserver.net
also, I wouldn't recommend Man for a new player, as it's 1 of the weaker, thus harder nations to play with.