A wide variety of phenomena involving heavy quarks are discussed. The general theoretical tools and methods are introduced in Chapter 2. The heavy quark spin symmetry and QCD multipole expansion are illustrated with simple examples. The peculiar strong dynamics near open heavy flavor thresholds is studied in Chapter 3. A general heavy quark spin decomposition is worked out to understand some unexpected experimental results. Two additional effects of strong dynamics are pointed out: mixing of partial waves and isospin violation. The long-range pion exchange interaction between heavy mesons dominates over other short-distance interaction near the thresholds region, which results in enhanced mixing of partial waves. The isospin violation in S-wave heavy meson pairs is calculated in all orders of isospin breaking parameters and the result is sensitive to a strong interaction parameter which can be used to probe the property of strong interaction. These predicted effects have nontrivial experimental implications, which can be studied in future experiments. Chapter 4 devotes to understand the properties of some exotic resonances discovered recently by the experiments. We propose Zb(10610), Zb(10650) and X(3915) as hadronic molecular states, while Y (4260) and Y (4360) as mixed hadro-charmonium states. The ω transition between quarkonium states is also discussed. In Chapter 5, the various decay channels of hb(2P) are carefully examined. We point out the data may indicate a possible violation of the popular theoretical picture about quarkonium. A particular type of heavy baryon decay is considered in Chapter 6, which may provide a clue about strong diquark correlation and the hidden scale in QCD.