In general, it's not so good value to have breakfast at your Paris hotel, unless it's included in the price. Our hotel had an "international" buffet for € 23!!! That's a lot of money, you could have a perfect steak for that price. And it means you usually overeat, as I did, when we were unexpectedly offered breakfast on our last morning (long story). You can usually have breakfast in cafés, but I'd recommend finding a good baker with a breakfast formula. We got lucky at what used to be my family's local bakery. They had a full brekkie for 6 euros, with a huge piece of fresh baguette with butter and jam, a perfect croissant, a glass of OJ and including a generous pot of Mariage tea for one. Heaven! Plus you get to witness the locals' life and banter insead of sitting among fellow tourists or -worse, ha ha!-business people.
Another favourite area of mine, but you didn't need me to tell you to go there, is Pigalle, Montmartre and the Sacré-Coeur. The area at the bottom of the Sacré-Coeur is particularly interesting for sewing enthusiasts as it hosts several fabric shops, among which the cheap Déballage Dreyfus, and the fabulous Reine, which has many many Liberty tana lawn prints as well as bias tape, in smaller specialized shops you can also get hold of affordable pieces of lamb leather in all colours, and if you are with non-sewers, there are lots of interesting shops in the streets leading to Abbesses, and what's more, fewer of the ubiquitous chain shops. If you get up to Montmartre -watch out for those guys trying to tie knots around your wrists oh and avoid those guys with the card/cup games as well- you can go down the other side and see the vineyard.
I really like Le Progrès in that area (7 rue des Trois Frères 75018 ), you can get a really decent meal or just quench your thirst there on the way up or down the Sacré-Coeur.
Another rad neighbourghood for happy hour drinks and dinner is Bastille. Up Rue de la Roquette you'll find many charming bars and lots of touristy places-avoid dining there though. A bit farther off the main streets you'll find many nice restaurants, among them Le Bistrot Paul Bert (18 rue Paul Bert, 11°), which has been praised by many already. Alas we got there on Sunday evening and predictably it was closing day. We still managed to get a decent meal somewhere else.