As a noun:
* My mentor helped me navigate the challenges of starting my own business.
* The young artist found a mentor in the renowned sculptor.
* The program pairs at-risk youth with experienced mentors from the community.
As a verb:
* The experienced engineer mentored a group of new hires.
* She mentored her younger sister through her first year of college.
* The company mentors its employees through professional development programs.
You can also use "mentor" in a more figurative sense:
* The wise old owl served as a mentor to the young fledglings.
* The book became my mentor on my journey to self-discovery.
The specific use of "mentor" depends on the context and the intended meaning.