My main advice is to not worry about the checklist of big tourist sights to see. If the only reason you want to go paris is the Eiffel Tower, it (probably) isn't worth it. If you want to experience what paris feels like, what real a real parisian baguette tastes like warm, or what spending the afternoon at a sidewalk cafe on a bustling street is like, then you're really going to enjoy paris. The Eiffel Tower may still be the highlight, but try and make sure you'll enjoy the place you're visiting too. (I say this all without ever having visited paris, so take it with a grain of salt...)

I'd reccomend going to a large bookstore and perusing the travel section together, seeing what places sound like places you'd enjoy the most. Your trip sounds like a lot of fun.

Matthew