The central point of training resources at WGC for Nextflow and NF-core. If you find something better then please sumbit a PR.
Level 1: The official documentation for Nextflow, including beginner tutorials on how to set up basic pipelines.
Level 2: Adapting your pipeline into the NF-core template to supercharge open source science.
Level 3: Adapting the underlying code of Nextflow to suit your needs.