How to add custom post pages and an admin area with options?

Hi,

I am not sure what to search for, so I’m asking here…

I’d like to create a theme with some features like the ability for someone to add their own logo, background, custom header tags etc… also I’d like to create a ADD new post with extra info on posts like where they are located, what they do, etc… when they click on Add New Post.

I’d like to create my own framework and custom post pages.

What do you call this? How do I search for how tos? Sorry if this is already answered. If so, what should I search for?

Any thoughts or ideas? thanks!