By ideas that 'help us to get into satisfactory relations' James means ideas that are useful to believe. James is therefore an instrumentalist about truth. A few sentences later in the work you cited he says:
Any idea that will carry us prosperously from any one part of our experience to any other ... is ... true instrumentally.
In what sense is a belief useful? Interpreting James, Kirkham  suggests a few:
- The belief helps us to manipulate objects in the world.
- The belief allows successful communication.
- The belief leads to accurate predictions.
- The belief explains other phenomena.
Holding that a belief is true whenever it is useful is of course very controversial, and it differs greatly from more mainstream views that hold that things are true because of some objective and mind-independent facts. Indeed, for James, there are no mind-independent facts and he thus holds that truth and reality are relative.
In The Meaning of Truth (1909) James says:
Truth may vary with the standpoint of the man who holds it. (p. 135)
It's quite difficult to defend such a view. But I'll leave it at that.
 Kirkham, Richard, 1992, Theories of Truth: A Critical Introduction, Cambridge, MA: MIT Press.