  Transport and thermoelectric coefficients (including also spin thermopower)
of silicene nanoribbons with zigzag edges are investigated by {\it ab-initio}
numerical methods. Local spin density of such nanoribbons reveals edge
magnetism. Like in graphene, one finds antiferromagnetic and ferromagnetic
ordering, with spin polarization at one edge antiparallel or parallel to that
at the other edge, respectively. Thermoelectric properties, especially the
Seebeck coefficient, significantly depend on the electronic band structure and
are enhanced when the Fermi level is in the energy gap. However, these
thermoelectric properties are significantly reduced when the phonon
contribution to the heat conductance is included. This phonon contribution has
been calculated numerically by two different methods. Transition from
antiferromagnetic to ferromagnetic states leads to a large magnetoresistance as
well as to a considerable magnetothermopower. Thermoelectric parameters in the
antiparallel configuration, when spin polarization in the left part of the
nanoribbon is opposite to that in the right part, are also analyzed.
