Blue Clements (UVa M’Arch 2017) has made a series of Karamba Introductory tutorials as part of the Parametric Stuctural Design courses at the University of Virgina headed by Jeana Ripple.
The six part tutorial explains how to set supports, loads, assign cross sections, optimize cross sections and then evaluate the results.
Get the definition here: TU_Intro_BeamGrid.gh
These tutorials use Rhinoceros (Version 5 SR12 64bit), Grasshopper (0.9.0076) & Karamba (1.0.5) where Point Loads, Gravity, etc are separated into different components. The source definition has been created with Karamba 1.1.0 where all Loads are integrated into one component.