Dale hermao! There's no better place to learn salsa than Cuba, and have a great time going it.
US citizens are not allowed to travel to Cuba, hence need to get the entry stamp on a separate piece of paper when they do go. Other nationalities don't have that problem, and you shouldn't have difficulties passing through immigration with a Cuban entry stamp. Thousands of Canadian go there every year, and have no problem getting into the USA.
You won't need a visa, only a tourist card.
Cuba Visas are not required for nationals whose countries have signed visa exemption agreements with the Republic of Cuba (contact your nearest Cuban Consulate for more information) or holders of a Tourist Visa Card. Certain tour operators, travel agencies and airlines can issue a Tourist Visa Card valid for one single trip of 30 days, although the stay can be extended in Cuba. Cost is about US$ 30.00. Stipulations are that the traveller pre-books and pre-pays hotel accommodation in Cuba through an officially recognised tour operator and has a RT airline ticket. You will probably come under the "b" category.
http://www.wordtravels.com/Travelguide/Countries/Cuba/VisaProbably the easiest way for you to get to Cuba is through Mexico. You can get all the required documentation at the travel agent or airline booking your trip wherever you land up before arriving in Cuba. There are flights to Cuba from all North American, Central American, South American and most Caribbean islands, except the USA. The Mexicana daily flight is US$ 320.00 RT.
http://www.despegar.com/
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