Massive Open Online Courses (MOOC) are available worldwide and offer tons of topics, also about Linked Open Data (LOD). An easy way to enter the semantic web.
The Hasso Plattner Institute, Potsdam provides, for some years now, a course in Linked Data Engineering with a certificate. I did it some years ago and enjoyed it.
The French platform FUN offers a LOD course, too. (Thanks to Adrian at zazuko.com for the hint)
Step by step Bob DuCharme introduces RDF, SPARQL, LOD …