(Trump Image):
Dominating this image is a huge stained glass window showing a monk with a halo and holding an open book, and a silver cloud with a golden all-seeing eye above the monk's head. The window is in the stone wall of a castle or monastery, in an open, "atrium"-type area in a library that spans several floors. The viewer's vantage is from one of the mid-level floors across from the stained glass window.
(In Person):
The first thing usually noticed is the silence. There is virtually no noise whatsoever. The attendants (monks?) have an unbreakable silence about them.
The next thing usually noticed is the tranquility. There is an aura of peace, almost a compulsion, about the place. In fact, so strong is this sense of peace and tranquility, that anyone trying to speak loudly or act violently or in any other way violate the sanctity of the library, they must first succeed in a test of will, with the force opposing them proportional to the intended level of discourtesy or violence.
Beyond the atrium, the library is an unmappable, infinite labyrinth of bookshelves stuffed with books and scrolls, with an occasional small desk and stool or a table with benches that is, more often than not, occupied by one or more the silent bookkeepers. Finding a specific table or bookshelf unaided is all but impossible; every time Liam has tried this, he has wound up lost. However, once you give up and try to find your way back to the atrium, it usually takes no more than ten minutes or so to make your way back.
You can approach these monks (Liam has done so, himself), and ask them for a specific act of assistance. Asking them specific, probing questions about the nature of the library will be met with only a gentle smile and a shake of the monk's head. Ask one of them for food and drink, and he ("it"?; definitely not "her") will lead you through the labyrinth to a small table near the atrium with a bowl of a bland vegetable stew and a flagon of crystal clear water. Ask one for the privy, and he will likewise lead you to a small closet; once you're done, he will lead you back to where you found him.
You can also ask the monk for information on a specific subject -- other than the library itself, of course -- and the monk will lead you to a particular bookshelf, and will indicate which row of the bookshelf contains the books or scrolls wherein you can find the answer. Bear in mind, some of these shelves contain dozens of books or hundreds of scrolls, and the monk will not show you the exact book or scroll you need. Furthermore, the answer to your question might well be found only in parts -- part in this book, part in that scroll, but all such books and scrolls will be found in that particular shelf.
This question of yours can be a frivolous or as serious as you want, but it must pertain to some natural property or observed event. You cannot get the answer to something that is a closely guarded secret, for example, but you could find out about some obscure event from ancient history that has been all but forgotten back home.
Everything in the library, including visiting shadow-walkers, is protected to a degree by the library by the compulsive aura of tranquility. Assuming the person intending violence has succeeded at the test of will, if that person persists in being violent, he will fade away and disappear. (As best Liam can determine, the offender is Trumped away to some Shadow, usually -- but not always -- the one from which the offender came to the library.)
The rate of time in this Shadow is about midway between that of Amber and that of Chaos. Approximately three to four hours pass in the library for every hour in Amber. And, yes, the monks will provide a pallet for those who wish to "sleep over", but the pallet will be set up in a small monk's cell, with an easily opened door. (Liam says that these doors are somehow sound-proofed, probably to prevent visitors who snore from disturbing anyone else.)
Liam has not ventured "outside" the library. He says that he never found a door to the outside, nor a window that could be opened (and he was not willing to break either the great window nor one of the smaller frosted windows to find out what was "outside").