Tips for an amazing trip.
In Havana: Bishop's Street and NOT heed those who lead you to the "Good Social View Club" is horrible and they charge you very hard for a cocktail in a place that falls apart.
In Varadero: I recommend an all-inclusive hotel, in addition to being beautiful, in these hotels you are very well served on their private beaches.
He's got Euros or Canadian dollars. No American dollars. There's a foreign exchange rate in Cuba that drives anyone crazy, and they always overcharge you for being a foreigner.
Otherwise very rich, highly recommended.