A pdf version of this tutorial is available here: PDF. The R code used in this tutorial (not cleaned up) is available here: R.
If you are new to lavaan, this is the place to start. In this tutorial, we introduce the basic components of lavaan: the model syntax, the fitting functions (cfa, sem and growth), and the main extractor functions (summary, coef, fitted, inspect). After we have provided two simple examples, we briefly discuss some important topics: meanstructures, multiple groups, growth curve models, mediation analysis, and categorical data. Along the way, we hope to give you just enough information to get you started (but no more).