La Rive Gauche is where the artists, writers and philosophers are --the heart of bohemianism & counterculture. Stroll around, soak it in! Say hi to John for me!
Le Pont Des Arts is the only pedestrian bridge in Paris with a beautiful view of the Seine river. I used to cross it everyday to go to Art School.
You like ice-cream. And this is one of the oldest and best ice-cream parlors in Paris. It's on the gorgeous Iles St Louis, the oldest Paris neighborhood.
La Hune is a fine art, photography, visual communication, and design bookshop. Highly recommended. Don't buy too many books, they're hard to carry back!
Traditional tea house with hundreds of teas. Head there when you're tired of walking for a relaxing break. A little touristy, but worth it.
Probably my favorite museum in Paris, mostly filled with Impressionist art. Make sure you go to the top and walk behind the clock. It's a really nice shot.
Le Bon Marche started in 1838 and is a now high-end department store. It's the setting of Emily Zola novel Au Bonheur des Dames.
No words can describe this patisserie. Eat as much as you afford!
I think you mentioned you need to do a bit of work. Here's a hipster coffee shop with good coffee and wifi.
If it's sunny, head to the Musee Rodin and enjoy the beautiful sculptures in the gardens.
On your way to the Eiffel tower, walk through (and eat) in one of the many excellent restaurants, bakeries, cheesemongers of Rue St-Dominique.
Try some Aligot, a traditional dish from le Sud Ouest made from melted cheese blended into mashed potatoes, and served with a steak or sausage. It's amazing.
When I was a kid, my grandma used to take me here to rent one of the small boats that you push from one end of the fountain to the other. You'll see. Try it!
La Sorbonne is the most famous university in Paris abroad. It's also where Mai '68 started... Sous les pavés, la plage!
The Catacombes de Paris is an underground ossuary which holds the remains of about six million people. Check their website for opening hours. Lines are LONG.
Out of the way, the BNF is one of the most impressive libraries in the world. Since you like books and architecture, you should swing by.