During my preparation for the IBO, a few times I encountered problems with graphs depicted on logarithmic or semi-logarithmic paper. Thus, I share with you a tutorial how to use this paper. Keep checking this or any other of my posts because they are constantly updated with new information.
Some good practical examples of log graphs:
Big thanks to http://www.lhup.edu/~dsimanek/scenario/errorman/graphs2.htm.