The documentation on this could stand to be improved. In Squeryl 0.9.5, for typical use, you want to:
import org.squeryl._
import PrimitiveTypeMode._
The latter import will bring in most of what you need.
In Squeryl 0.9.6 PrimitiveTypeMode
is deprecated and you would define your own EntryPoint object that you would import from instead.