Common casino rules are these: Pots are split as evenly as possible down to the smallest betting unit of the game. In a typical small game, that's usually a $1 chip, but in some games it might be a $5 chip or even bigger. The "odd" chip(s) left over after everyone gets the maximum equal amount are distributed differently depending on the game being played.
In games with blinds (like Texas Holdem and Draw games), extra chips are given to the players in order after the button. That is, eldest hand gets first odd chip, second eldest hand gets the next one, etc. In stud games, the odd chip(s) are given to the player with the highest single card in his hand (using the same high-card-by-suit ranking as for bring-ins), whether or not that card was played, then second-highest, etc.
In high-low split games, if the odd chip is caused by the initial split, it goes into the high pot, and then each pot is awarded as above. Some casinos have a special rule that if there is a single winner for high and multiple winners for low (a common occurrence in Omaha), the first odd chip goes into the low pot.