Book excerpt: Generation and manipulation of spin is of central importance in modern physics. This intense interest is driven in part by exciting new phenomena in spintronics such as spin Hall effects and spin transfer torque as well as by the growth in new tools enabling microscopic studies. Ferromagnetic resonance (FMR) is a powerful technique to study macro-scale spin ensembles, and an effective method to generate pure spin currents. Combined with scanning capability, it can be used as a spin sensitive microscopy with nano-scale spatial resolution to bring fresh insights in spintronics and achieve local excitation, manipulation, and detection of spin. In the first part of this thesis, I will briefly introduce the field of spintronics. In the second chapter, I demonstrate the use of FMR spectroscopy to study the static and dynamics properties of novel materials. In the third chapter, I present the FMR spin pumping technique in ferromagnetic material/normal metal bilayer to characterize the spin Hall angles for a series of 3d, 4d, and 5d transition metals with widely varying spin-orbit coupling strengths and demonstrate that both atomic number, Z, and d electron count play important roles in spin Hall physics. Those work studies the spin dynamics and transport across the interface defined by material discontinuity in macro-scale sample. To study nano-scale structures, in the forth and fifth chapters, I describe probing and imaging spin dynamics using spin wave modes confined into microscopic volumes in a ferromagnetic film by the spatially inhomogeneous magnetic field of a scanned micromagnetic tip of a ferromagnetic resonance force microscope (FMRFM). It shows the characteristics of the localized mode can be broadly tuned by appropriate selection of the orientation of the tip moment relative to the applied uniform field. Micromagnetic simulations accurately reproduce our experimental results and allow quantitative understanding of the ferromagnetic resonance force microscopy spectra. These results provide a universal method of generating and understanding the tightly confined localized modes in various measurement geometries and material systems with increased freedom in the choice of tip and material, and paves the way to improved spatial resolution for imaging using localized spin wave modes. At last, I demonstrate a design of room temperature FMR force microscope with both imaging and transport capability to study and image spin dynamics and transport across the interface defined by the magnetic textures with nano-scale resolution. The sixth chapter is a conclusion of the entire dissertation.