Nearest airports are at Poznań Lawica: http://www.airport-poznan.com.pl/en/ or Warsaw Okecie Airport.
Have a look at this website: http://www.e-lowcost.net/.  If you land in Warsaw you may take an intercity train to Konin.
And when you arrive in Konin, you can get a taxi or take a bus or change a train.
 If you decide to land in Poznań reaching Slupca is much easier, both because it is closer to the town and there are direct bus or railway connections.
It is important to have a map of Greater Poland, available in newsagent's.
Nearest airports are at Poznań Lawica: http://www.airport-poznan.com.pl/en/ or Warsaw Okecie Airport. Have a look at this website: http://www.e-lowcost.net/.  If you land in Warsaw you may take an intercity train to Konin. And when you arrive in Konin, you can get a taxi or take a bus or change a train.  If you decide to land in Poznań reaching Slupca is much easier, both because it is closer to the town and there are direct bus or railway connections. It is important to have a map of Greater Poland, available in newsagent's.
Słupca