A few questions about multiple scenes, and menus

I'm just starting with Unity2D, and I ran into this hurdle.

I want to make my menus be each in their own scene. Press start? Brought to the pause menu scene. Select "Party" and you're bought to the Party List Scene. Pressing B brings you back to the main menu, and again brings you back to the game right where you left off.

But here in lies the problem, I really only know how to change scenes via LoadLevel, which would mean it would have to un-load the game to load the menu scene.

So my questions are:

1) Is there a way to load two scenes and switch between them freely without unloading/reloading

2) Is there a way to have multiple scenes on the screen at the same time or embedded in other scenes? So maybe the menu scene could pop up over the game scene?