The systemic analysis of cations is a flow chart of inorganic analysis, am I right? Group I is the insoluble chlorides, group II is the acid sulfides, etc? Get just about any general chem text, flip to that chapter and try to study it. The topic really doesn't build on other chapters, it's about following flowcharts, and memorization, developing an analysis plan, and memorization, confidence, and, oh yes, memorizing stuff you'd normally just look up in the real world.