Football (Soccer) management Game?

New here :)

How would I go about starting to develop a football management game?

What I basically have in mind is the user able to choose a team, then they have to pick the players, and can buy players etc and play matches.

1: What sort of code would let me genereate a match result based on hidden player ratings (Each player has a hidden rating, the game adds this up, compares it with the other teams total and the highest wins)?

2: How could I make this happen for the Computer controlled teams (Ie, the other teams in the leauge that are no playing the human, and are not human controlled?)

Any help would be most appreciated :)

You might be better just to start writing the game and then asking more specific questions when you get stuck, as it's a bit vague at the moment.

As for things like making computer teams play each other, don't worry about it, it should be easy once you've got your main game engine sorted.