If your are coming by train to Malmö, the closest station to the bookfair is the stop: Trianglen.
There is many buses that comes to Malmö from Göteborg, Stockholm, Copenhagen. And the main stop is Central Station.
If you are coming to Malmö by plane, we recommend you to check first at Copenhagen Airport (Kastrup). There is more options to get there and the connection is easy to Malmö (train and bus). Otherwise there is a small airport outside Malmö, called Sturup.
The E6 or E65 arrives to Malmö through Sweden. Otherwise E20 comes to Malmö from Copenhagen. Remember that cost money to cross the bridge by car from Copenhagen to Malmö, and if you are coming from south, don't forget to book in advance the ferry between Puttgarden and Rödby. Alternative is drive around Denmark.