Brazil is large enough that a single trip usually covers one or two regions: Rio de Janeiro and the southeast coast, the Amazon in the north, the northeastern beaches around Salvador and Recife, or Iguacu falls on the southern border. Flying is the practical way between them.
The guides on this page cover Rio de Janeiro and Brazil overall. Seasons are reversed relative to Europe, and Carnival — dates shift with the calendar, usually February or March — fills hotels and raises prices well beyond Rio. Urban safety varies sharply by neighbourhood and time of day in the largest cities, which is worth researching locally rather than generally.