In this paper, we discuss the use of broadband microwaves (MW) (up to 20 GHz) to characterize organic and hybrid silicon-organic thin films meant for insulation applications in micro- and nanoelectronic devices. Specifically, we will take advantage of MW propagation characteristics, to extract and examine the relationships between electrical and mechanical properties, and the chemistry of prototypical materials. The impact of moisture on the electrical behavior of any material defects will be evaluated from the impact of thermal anneal at modest temperatures on the samples. These studies will shed light on the chemical changes that occur within the dielectric films that could impact the performance and reliability, as well as provide basis for rational selection of organic dielectrics for integrated devices.