Cafe - we had an excellent traditional meal at Cafe Constant (Christian Constant now has 4 restaurants on a street in the 7e). I think this one was about 35 Euros.
Small cafe - over on the rue Oberkampf, we sat down at a little place called L'Estaminet for a tasty lunch very reasonably priced (2 of us paid less than 20 Euros, including some wine)
There's a great underground restaurant called hidden kitchen, but I believe they are booked solid through September - http://www.hkmenus.com/ - 80 Euros prix fixe (all included)
Haut Cuisine - a 3-star Michelin restaurant! Guy Savoy (we did a lunch menu - the food kept on coming!). Over in the 17e. Sublime, and bread pairings with our food. http://www.guysavoy.com/en
Falafel - L'As du Falafel or Chez Marianne both are excellent on the rue des Rosiers in the Marais. These run about 5 euros each.
Macarons - we tried 4 or 5 different ones. Hands down the best are Pierre Herme (esp salted caramel). On rue Bonaparte in the 6e.
Crepe - we had a salted caramel with chantilly cream crepe done up traditional Bretagne style at Breizh Cafe on rue V-d-Temple in the Marais.
Cheese. The ladies at Barthelemy in the 6e/7e border will look after you.
Cooking School. Marguerite's Elegant Home Cooking (but act quick, as she's moving to Seattle next month!) - http://www.elegantcooking.