As a newbie, (and you are only a newbie once), I figured that I would contribute to something i have a little experience with, and which can be a bit of a conundrum at times - dining in Paris on Sundays and Mondays.
About a year or more ago (Nov 2009 to be exact), my wife and I flew in for a brief stay in Paris. During preparations, I realised that dining options would be curtailed. Landing on a Sunday, we went for lunch to Brasserie Lorraine (2 Place Ternes, 75008 Paris , 01 56 21 22 00, Metro: Ternes). Upon entering the brasserie, we came across Donald Sutherland about to leave. He seemed in fine fettle, and seemed to have enjoyed his lunch. A good sign. We had a simple but excellent lunch of fish soup and a quiche lorraine, and a half bottle of Macon-Lugny. For dinner, I had reserved at La Grand Cascade, Allée de Longchamp, 75016 Paris (Bois de Boulogne), 01 45 27 33 51. It was originally the private pavilion of Napoleon III, and is very impressive. They had a reasonably priced menu (reasonable is relative, for Paris), the “menu du marche”, served lunch and dinner, for 86Euro, which includes 3 courses, plus 2 glasses of wine, water of choice, and lots of little extras such as amuse buches and ameuse geules …When you order the menu, you will have to deal with the inevitable sommelier and his “oh … you are choosing the formula” … and he manages to modify formula into a word of at least 7 or 8 syllables … the formula being 2 glasses chosen from several different house wines (none too shabby I might add 
. The food is good and the service relatively proper. The following day, we went to a favorite of mine for lunch, Caves de Petrissans, on Avenue Thiel in the 17th. They are open Mon-Fri, and have been since 1895. A business passed down from father to son. They are in the business of providing pleasure, and pleasure they do give. Entree was a celeriac remoulade for my wife and slices of smoked duck breast on a bed of lentils for me, accompanied by a Volnay from Jean-Marc Boillot (06). I was wondering why so many locals were leaving behind so much wine at lunchtime and also why they ordered bottles if they were not going to finish the bottle. The owner explained afterward that it is an old custom to sell wine by measuring how much was actually drunk, and this is how they operate. I like this system. They also have a wine store and you can order from the store at retail prices, by paying a supplement. I had asked the owner about white Beaune-Greves and he didn’t have any so he made a phone call to a buddy, and said that there was a tasting in Paris the following day and I was welcome to attend as a guest of his buddy, if I wished. How very kind. We had to leave Paris, and could not, but for oenophiles, or simply hungry people in search of tasty food, you could not do better then spend a happy few hours at this “cave”. Hopefully, this will add to readers options when they visit Paris on weekends.
Thanks for the guide and welcome to the board.
Sounds like a great couple of days. Welcome to the board (my brother lives in Montebello, by the way).