Appearence and choices made in the previous game get imported to the next.
ME2 uses a different skill system as ME1, but you get bonus starting experience after your character level in ME1 (more XP, the higher your level was in ME1, thus you start ME2 at a higher level). Also, if you completed some stuff in ME1 (having a certain ammount of credits, bought certain weapon licences) rewards you with bonus starting credits too. A portion of your morality points also carries over to the next game.
Your character class matters not, as you can choose to keep the old or choose a new one at the start of the game. (I don't really understand though what you mean by playing as a human, as you can't be anything else...)