  We review some aspects of the renormalization group method for interacting
fermions. Special emphasis is placed on the application of scaling theory to
quasi-one-dimensional systems at non zero temperature. We begin by introducing
the scaling ansatz for purely one-dimensional fermion systems and its extension
when interchain coupling and dimensionality crossovers are present at finite
temperature. Next, we review the application of the renormalization group
technique to the one-dimensional electron gas model and clarify some
peculiarities of the method at the two-loop level. The influence of interchain
coupling is then included and results for the crossover phenomenology and the
multiplicity of characteristic energy scales are summarized. The emergence of
the Kohn-Luttinger mechanism in quasi-one-dimensional electronic structures is
discussed fo both superconducting and density-wave channels.
