As y'all now know, I spent a semester during college living with a French family in Paris, and I absolutely fell in love with the city. Tod had never been to Paris before our honeymoon, and so when we decided to spend some time there on our trip, I really wanted him to be able to get the real feel of the city. In my opinion, one of the best ways to get the real feel of a city is to pass on a hotel and rent an apartment instead. You want to do your research beforehand because you want to know the exact area in which you want to stay, and you want to make sure you understand what you're getting. There's obviously a lot of trust involved, but you often can save a bit of money by going the apartment route. It's great to have a kitchen or a kitchenette, as well as laundry facilities, and, as I mentioned, it's a great way to get a little closer to a particular neighborhood--to feel like you're living in another place if only for a brief moment in time.
There are plenty of websites where you can search for vacation rentals, but we chose to go with flipkey.com, which worked great. We found a wonderful spot on the Ile Saint-Louis--a perfect, central location for anyone new to Paris who wants to explore both banks.
Our apartment was on the top floor of an ancient building very close to the Seine on a very quiet street. We had some idea of what to expect, and one of the things we expected (based on previous renters' reviews) was a whole bunch of stairs.
And heading down.
It actually worked out great for me because I just used all of the stair-climbing to justify my entirely-too-frequent bakery stops for pain au chocolat. If you ask me, there is nothing in the whole world that that smells or tastes better than fresh (still warm!) pain au chocolat.