Multiple pictures in 1 post – theme coding

Hi there

I will probably start building a theme for a specific site and before I start I want to get all the ideas how to implement everything.

The Thing is, I’d like to have a possibility to display 3-10 pictures in my post (kind of a sidebar).
Now, is there a way to have like little ‘galleries’ for each post?

The pictures just shouldnt be in the text itself, but rather in another div, all displayed one below the other.
What I imagine is, to kinda have a button in my window, where I write my new post, and on click I could upload several images, which are then displayed in exactly that post.

I’m glad for any link (for example to a free theme, to inspect how they did, or to a forumpost.. whatever), or any hint how to manage to do this.
Or if there already exist som plugins.. etc etc.

Just feed me with your experiences. would be a lot appreciated.
Thanks!!

cheers