I will present results of the re-determination of the Classical T Tauri Stars locus in the JHK color-color diagram, and show how our disk models, with different parameters, reproduce near-infrared data from different star-forming regions within our solar neighborhood. I will also present preliminary results of a study of the inner regions of protoplanetary disks, with an emphasis on the transition zone where dust sublimates and forms an inner rim, leaving only gas to persist. In particular a new approach to model the geometry and emission of the inner rim. The characterization of this region is crucial for reproducing observational signatures, and for getting more insights into the dust composition and properties in the regions where planets are formed and a significant number of exoplanets have been observed.
