Shinkansen Tokyo-Nagano; Shinano-Tetsudo line Karuizawa-Nagano; Japan Railways bus from Matsumoto airport.
Walking will mostly do; there are plenty of city buses.
Tree-lovers will want to spend a couple of hours in the Castle garden, 1 km NW of the station.
Hill-lovers will enjoy Taroyama (___Y_R), 1164 m, 2-3 hours from the station (head due north until forced to bear right).
Ramen everywhere.
Toyoko-inn is just NW of the station; 8080 for a double with breakfast (April 2009).