A general tutorial for Protégé (desktop and web-version) can be found at the Protégé Wiki.
The best Protégé tool for looking at OWL semantics is the desktop version of Protégé, which is a visual front-end to the OWLAPI.
However, for collaborative curation of OWLs it may be better to use the WebProtege. We host our own copy of WebProtégé.
