Every person going to Cuba as a tourist needs a passport valid for at least one month beyond the date of your expected departure from Cuba, and a tourist card (visa).
The tourist card is generally provided by airlines, or can be obtained from a Cuban government office abroad in the case of privately organized flights. It can also be purchased at certain airports in Canada, and abroad.
The tourist card allows its holder to stay in Cuba for 90 days (for Canadians only, 30 days for other foreign nationals) from the date of entry into the country, and is valid for 1 entry into Cuba. For a stay of more than 90/ 30 days, you can request an extension of another 3 months at any tourism office in Cuba, for a maximum stay of 6/4 months. Children, regardless of their age, also require a tourist card, even if they are registered on their parents' passports.
Note that a tourist card is only applicable when you are staying at a hotel or at a private house legally renting in Cuba. If you want to stay at a friend’s place you should apply for a Personal Visa.
The above information on entry and exit requirements has been obtained from the Cuban authorities. However, these requirements are subject to change at any time.