Brad Johnson starts at the beginning and works his way up to one of the most challenging strength positions on rings.
I recall how many of the best gymnasts in the world had trouble holding a front lever when it was included in the (now defunct) Olympic compulsory routines.
Good article. The only addition I have is use a particularly demanding spotter. A spotter who reduces the resistance just enough to keep you in the correct position.
The Front Lever: A Hard Core Exercise — PowerAthleteMag.com