Generally, seats on the left or east or facing the door are seats of the honor.

For a round table, the seat facing the door will be for the guest of honor. The importance of the seats to the right and left hand are in descending order with their proximity to the seat of honor, and the ones on the left are better than those on the left if the their distance to the honored seat are just the same.

For a square table, if there are seats facing the door squarely, then among them the one on the right end is for the guest of honor. And if there is no seat facing the door, then the seat on the right end of the east sides of the table would do.

For a grand banquet, the order of the desk shall be arranged as follows: the top table shall always be in the front or the center, the 2nd, 4th, and 6th table shall be on the left, and the 3rd, 5th, and 7th table shall be on the right. And the host and guest shall be seated according to their status and the closeness to the host. The host should arrive in advance and wait to usher in the guests, while the guest should be seated where the host arranged him to.

Generally if your boss is going to present at the banquet, you should direct the boss to the main seat and the most prestigious guest immediately on the left hand of the boss, unless the guest is of a very high rank.