The talk discusses basic nanoscale heat transfer and energy conversion principles, nanomaterials development, and advances made in the field of thermal and thermoelectric transport characterization methods. Self-constructed nanostructured networks (SCNN) induced within composites of epoxy-silver nanoparticles at temperatures low enough to be useful in electronic packaging lead to two orders of magnitude enhancements in thermal conductivity. Thermoelectric transport investigations in nanomaterials produced by a novel microwave stimulated synthesis technique show high power factors as well as unprecedentedly low lattice thermal conductivities through a combination of impurity doping and nanostructuring. Advances in the field of thermal and thermoelectric transport characterization methods include development of a scanning microprobe technique to measure simultaneously, in contact mode, the thermal conductivity and Seebeck coefficient, and to perform thermal conductivity characterization in non-contact mode. A method to extract the individual thermoelectric properties and electrical and thermal resistivities between contact electrodes and thermoelectric samples is also presented.