We investigate the importance of nitrogen ions within Saturn's magnetosphere and their contribution to the energetic charged particle population within Saturn's inner magnetosphere. This study is based on the Voyager observations of Saturn's magnetosphere and Cassini observations. The latter have shown that water group ions dominate both the plasma and energetic particle populations but that nitrogen ions over a broad range of energies were observed at ~5% abundance level. In the outer magnetosphere, methane ions were predicted to be an important pickup ion at Titan and were detected at significant levels in the outer magnetosphere and at Titan. O+ ions were found to be the dominant heavy ion in the outer magnetosphere, ~60%, with methane ions being ~30% of the heavy ions and N+ being a few percent. The two major sources of nitrogen ions within Saturn's magnetosphere are Titan's atmosphere and primordial nitrogen trapped in the icy crust of Saturn's moons and its ring particles deep within the magnetosphere. It is important to understand the source, transport, and sinks of nitrogen in order to determine whether they have a primordial origin or are from Titan's atmosphere. The energetic component is important, since it can come from Titan, be implanted into the surfaces of the icy moons, and reappear at plasma energies via sputtering obfuscating the ultimate source. As we will show, such implantation of nitrogen ions can produce interesting chemistry within the ice of Saturn's moons. The emphasis will be on the nitrogen, but the oxygen and other water group ions are also considered. We argue that neutral clouds of heavy atoms and molecules within Saturn's outer magnetosphere may be the dominant source of energetic heavy ions observed within the inner magnetosphere. Pickup heavy ions in the outer magnetosphere have energies ~1--4 keV when born. If they diffuse radially inward, while conserving the first and second adiabatic invariants, they can have energies greater than several hundred keV inside of Dione's L shell. We will show how observations relate to the various sources and acceleration processes such as ionization, collisions, wave-particle interactions, and radial diffusion.