Shear Force and Bending Moment Diagrams: This website is useful because it explains point loads and point moments. It also explains step by step equilibrium moments and forces, and it gives you a brief example of them and how to derive/draw shear forces and bending moment diagrams.
Shear Force and Bending Moment Diagrams: This is a good website, provides a great deal of explanation for the formulation of equations. Displays the diagrams that correspond to the different loads and forces; this allows you to select the most appropriate equation. It also explains shearing force and bending moments.