From what i understood, in Vajrayana tradition, it is important to have a fully prepared master. I remember that I read that the process of "testing" the master (to see if it is a genuine one or a fake one?) before embarking on the path could take even 12 years (!). Is this true? Can someone give me some quotes, or some tittles to read in detail about this?
Well, in the beginning, a safe bet is to pick a lineage head like HH Dalai Lama, HH Sakya Trizen, one of the Karmapas, etc.
Then, later, when one has more knowledge and so on, one can choose other teachers.