This room has no murals, but "in finish and furnishings it is the grandest of all the large ordinance rooms within the walls" of the temple. Same as the Terrestrial Room is has large mirrors, paintings, and chandeliers, but it is more "suggestive of conditions yet more exalted." Instead of theater-style seating for instruction it has tables with floral arrangements as well as comfortable sofas and chairs (Talmadge, 207-209). The Celestial Room "symbolizes life as eternal families with our Heavenly Father and His Son, Jesus Christ", and represents the glory of the highest degree of heaven. (Temple brochure, LDS Church). The Celestial Room is so called because it is symbolic of the Celestial Kingdom in LDS theology. Thus, the Celestial Room is a quiet and reverent place, where ANY individuals may stop to pray and meditate. In most LDS temples, celestial rooms are elegant, beautiful, and brighter in decor than other parts of the temple.

For the most part, all the answers to your questions about the Celestial Room are the same as for the whole temple.
The temples themselves are sacred, and not everyone is allowed inside. Only members who are in good standing, that is, who keep the commandments and have a testimony of the gospel, are allowed inside.
Special clothing is worn inside the temple; they wear white clothing that is respectable to the sacred environment inside.
To my knowledge, there are no special ceremonies or ordinances that occur within the Celestial Room, but those take place in other rooms specially set apart for those ordinances. Rather, the Celestial Room is a special and quiet place where the holy spirit is strong, and so many people come there to meditate, pray, and ponder. People are asked to keep any conversations or talking to a whisper inside there, so as not to disturb the peace that others may be feeling.

Anyone who wishes can go inside the temple, and the celestial room, BEFORE it is dedicated. The Church of Jesus Christ of Latter-day Saints holds open houses before dedicatory services where anyone can go through and ask questions to individuals who are there. After the dedication, only those who are members of The Church of Jesus Christ of Latter-day Saints that live up to certain standards can go into the temples (not all members can go in).

Inside the celestial room no one eats, but they do converse quietly and pray too.

As the House of God, temples are places of worship set apart for members to make promises with God that they will live high moral standards. We show our love and devotion for God by making these promises.

If you have more questions, then see if there is a temple being constructed in your area. About two months before the temple is dedicated there will be an open house where you can ask more questions.