Researching the methods shown by preachers

yesterday i watched a video about a lecture given by Sri acharya rajaneesh (aka osho). my brother sent it for me on my request. i want to know more about his method of teaching and his philosophy.Many many good teachers are and were available in india to explain about our indian philosophy or universal truth. I treat them like this. Many gurus are very good in explaining the available subject in different ways. They tell how we should understand . But very few , really very few are available who teach us what we should understand. they can teach how also. But the subject to contemplate would be given only by these avatars, maharshis who have actually travelled in the path. some times i find it interesting to listen to the ordinary preachers, or semi gurus who are good at explaining and diverting us to goal, some how by inspiring us in some way. But i am not sure if they reached the goal. The real avatars or enlightened gurus travelled the path, and avatars them selves are the goals too. so my tentative plans are to study rajaneesh, Jkrishnamurthy,ramana maharshi, arabindo to know how they showed the way. Out of the above some are really enlightened gurus like ramana maharshi. The problem is , i am incompetent enough to decide who is real guru or enlightened. Since i am searching for me, i am compelled to use my yardsticks which are purely subjective. Yet , i hope i get some benefit out of my search. My first impression with acharya rajaneesh is not very impressive. Yet i will continue to know more.