This is probably the mother of all Lightroom image processing courses out there. It covers the raw development process with all its ins and outs in great detail, and it also takes a look at the other modules in Lightroom. It is an impressive 10+ hours long and you will be taken through the processing of 50 images. Pye Jirsa from SLR Lounge explains all the tools and lots of nifty techniques for an effective and efficient workflow. Pye is primarily a wedding photographer, but the sample images (included in the course) also include landscapes and portraits. So, in terms of genre, Pye should have you covered.
Lightroom 6 & CC have been released earlier this year. The software has been improved a lot over earlier versions, and in this video course by French photographer and photography instructor Serge Ramelli, you will learn everything there is to learn about the standard in photo management and photo editing software. Serge takes you on a complete tour through Lightroom showing you each module. He also demonstrates the newer features with some sample workflows. If you are new to Lightroom and trying to learn what it can do and how to do things quickly, this course is for you.