These videos are a little boring however, they clearly explain the procedures needed to analyze Trusses. You should watch them and then do a lot of practice problem on using these techniques.
Truss Analysis: Method of Joints
#1: Force Acts in same direction as the member, meaning members are only in compression or tension
#2: Equilibrium applies everywhere
#3: Forces can be split into components.
Tricks of Trade:
1. The easiest joints to analyze are those at which all forces and members are either horizontal or vertical.
2. Start analysis at a node where there is only one unknown.
Truss Analysis: Method of Sections