May, June, September and early October are the sweet spot. The weather is good, the city isn't packed, and most places are open. August is tricky because a lot of the best restaurants and bakeries close for two or three weeks. December is magical for Christmas lights but cold and grey. July is hot and crowded but Paris Plages on the Seine is worth seeing.

Four full days is the minimum to feel the city without rushing. Five or six lets you breathe, do a day trip to Versailles or Giverny, and actually sit in cafés instead of running between sights. Anything under three and you'll just hit the big monuments and miss what makes Paris Paris.

The Marais, Saint Germain, or the 7th if it's your first time. Close to everything, walkable, safe, and full of good food. I'd avoid staying right next to Champs Élysées or Gare du Nord even if the deals look tempting.

The metro is fast, cheap, and goes everywhere. Buy a Navigo Easy card at any station, load it with a carnet of ten tickets, and you're set. Walk as much as you can though, Paris is one of the rare big cities where walking is genuinely the best way to see it.

For anything popular, yes. Two to four weeks ahead for hot spots, the morning of for most bistros. Bakeries and cafés never need a reservation, just go.