Solomon starts on the last step in finishing the Temple. He has the Ark of the Covenant brought into the Temple by the Levites. These are the guys Moses trusted to handle all the stuff with the Ark back in Exodus; they're transport specialists, among other duties.
Solomon throws a huge party. He invites all the VIPs in Israel to come see this big moment. They watch the Ark enter the Temple and the king has so many animals burnt as sacrifices that people lose track. Animals were definitely harmed in the making of this spectacle.
The Ark finds a place under the golden angels. Inside the Ark are the two stone tablets that Moses brought down with him from Mount Sinai. They've got the 15—oops, 10 Commandments written on them.
Once the Ark is safely in the Holy of Holies, the Temple singers strike up the band and start praising God.
The Chronicler describes the Temple as "filled with a cloud." This is the same cloud that followed the Israelites around in the desert back in Numbers. It's a sign that God is present in the Temple. He's come home and obviously approves of his new digs.