Customising Theme-options to twenty twelve

Hi,

I’m wanting to add certain theme options to twenty twelve as I’ve used is as a boilerplate for my current website project.

At the moment I need multiple sidebar’s for each page, and to do this I need to implement certain functions for this to work, Like custom widgets and images.

I want to use anything thats already in the wordpress API to make this clean and relative.

Anyone know what the file is called or how I can start implementing the actually theme options. Its not in the normal folder of INC/THEME-OPTIONS inside the current theme.

Thanks for any guidance on this.