The library was created by Aimé-Samuel Forney to promote artistic craftsmanship for the city's workers. Forney, a philanthropist who left no heirs, instead left the city a legacy that funded a new type of institution: a professional library that Parisian workers could use to perfect their skills.
The Forney library, originally located in Forney's neighborhood of the Faubourg Saint-Antoine (11th arrondissement), was the first library in Paris to stay open late so that visitors could make use of it after work.
It is not necessary to register to visit the Forney library. However, if you wish to borrow books, you'll have to register at the Accueil desk. Simply fill out a fiche d'information titled: Inscription dans les Bibliothèques de la Ville de Paris, present a valid photo ID (passport), and bring a small photo of yourself (to put on your membership card). With parental supervision, children can also receive cards and have borrowing privileges.
The library collection is located on 3 distinct floors. The reading room is spacious and divided from the stacks by a triple-arched screen of open stone lacework. The poster collection is up a winding stone stairway inside one of the turrets. The collection includes decorative, graphic and fine arts as well as collections on wallpapers, textiles, posters and advertisements. On the 3rd floor, I found a book on sardine advertisements, which I thought was quite drôle.
As well as having computers (some with Internet access), there is plenty of seating and space to view books, make notes, and consult the library's many catalogs. However, the librarians are well-informed, friendly, and enthusiastic in their help, so if you have questions, I'd start with them first. For example, much of my research is not located at the Forney, but when inquiring whether or not they had information on the subject I was seeking, they were able to direct me to other libraries in Paris. Not only were they familiar with their own collection, but those of the other libraries as well.
If you wish to get online, look for a computer with a red dot on the top of the monitor (same place where you'd find the integrated camera on a laptop), enter your membership code (this number is below the bar code on your card), and your birthdate as your secret code (day/month/4-digit year of birth). Voilá! You now have access to the Internet for 1-hour. I presume you can sign-in again for another 1-hour session, however, I only needed to be online for about 30 minutes, so I didn't have a first-hand opportunity to find out. Besides, given that I can sign-in from anywhere, including home, I figured my time was best served exploring the many shelves of the library, which I did with great delight.
Visiting Paris' Bibliotèque Forney is a treat for any bookophile. For those who do not speak French, the library also has a pretty sizable collection of books in English.