It's somewhat overwhelming to start looking for your accommodations in Paris. There are literally 1000s of hotels and apartments to choose from and 100s of sites to help you choose/book them.
Americans can find European hotel rooms very small. Buildings in Paris are often centuries old and have been retrofitted for modern needs - adding private baths and closets. Even modern hotels often cater to the European business traveler who are accustomed to smaller rooms.
There are a few American chains, such as Holiday Inn, where you will find more familiar space and amenities. If this is your first time traveling on "The Continent" and feel a need for a haven of familiarity, this may be a good choice for you.
Hotels range from reasonably priced to a king's ransom.
When booking your own rooms, watch for non-refundable special rates and double check your dates before you click. As usual when choosing a hotel, read the reviews - but with a grain of salt. No one likes everything.
Be sure you understand the size of the room, beds, and what's included.
I have stayed in hotels but prefer apartments. These are great if you are on a tight budget. They also allow you to "live" in Paris. This is my favorite way to enjoy Paris and what I generally recommend unless you are just passing through Paris.
There are lots of places to search for apartments. But first, understand the lingo and what to expect: