i think ten lessons is kind of arbitrary, the way in which you evangelize/disciple someone will be different depending on the person and the circumstances you are in. however i think i understand the gist of your question:
I would say obviously the gospel: Jesus virgin birth, sinless life, death on the cross for your sins, resurrection for your salvation, and faith in his as your only means of justification.
however in a more systematic approach: you can try and hit certain topics, idolatry, sin, jesus life and death, the bible, worship.
it really all depends, there are a lot of great resources out there for mentoring, discipling, and evangelism: in terms of systematics:
if you are dealing with kids: bruce ware's, big truths for young hearts
a little older: da carson's, the god who is there
a little older: driscoll's, doctrine
much older: horton's, the christian faith
also there are a lot of great coaching and mentoring books:
the gospel coach: scott thomas
transformissional coaching
the be-with factor (this book is alright, has some great lessons and not so great lessons, so take it with a grain of salt)
