In 2009 the risk education for category B licences was extended to also include a section on drugs, alchohol, tiredness and risky behaviour. Each of the two parts of the compulsory risk education should comprise at least 180 minutes of teaching (excluding breaks).
If you want to practise driving outside of a driving school (i.e. with a private tutor) there is also a compulsory introduction course (duration: at least three hours).
For information about content see e.g. http://transportstyrelsen.se/globalassets/global/publikationer/vag/trafikant/korkort/bilder/all-about-driving-licences_eng_170-dpi.pdf
Other than that it is up to the individual to decide how much training to have before taking the test.