The main tutorial for new users is our 22 minutes getting started video that guides through the first steps of the most common workflow: schematics/netlist driven design. The video is also available for download and streaming on archive.org or on youtube.
After the getting started video, the easiest path is to follow this series of short videos:
There are a few video demos in the knowledge pool.
Per feature topical howtos are normally written in the searchable knowledge pool