There are various techniques for solving systems of nonlinear equations, and throughout the book, this type of equations appears consistently, in particular trigonometric ones. For this reason, the first section of this chapter provides a useful solution approach. Because the links of a kinematic chain, particularly SKChs (Serial Kinematic Chains), make their movements in three-dimensional Euclidean space, the mathematical tool by which these movements are represented is discussed. Another section, focus the attention to the kinematic modeling of SKChs in the sense of determining the relationship between the reference frame associated with the fixed link, and the reference frame associated with any other link of the chain, there are several criteria to assign the parameters involved in the formulation, and two of them are applied in this book. With the SKCh’s link parameters acquisition, the last section of this chapter is focused on providing the the design guidelines of the SKCh’s skeleton links.