Text building blocks
If you like my answer and it was helpful to you, consider upvoting and marking it as [accepted answer](http://meta.tex.stackexchange.com/q/1852) by clicking on the checkmark ✓ next to the score.
Drawing diagrams is super easy with PGF/TikZ. This particular package has an extensive [manual](http://texdoc.net/texmf-dist/doc/generic/pgf/pgfmanual.pdf) which also features basic tutorials to get you started. Once you have obtained a basic sketch with it you can come back here and present your specific problem as a [minimal working example (MWE)](http://meta.tex.stackexchange.com/q/228).