transference is a very tricky part of therapy and is so much more common than people think and/or talk about. the fact of the matter is that ALL therapists are trained and taught how to deal with transference the proper way. when dealt with properly transference can be a very helpful and healing tool in therapy. but on the other end of the spectrum, it can also destroy the therapeutic benefits and hurt you. this all depends on the therapists willingness and ability to deal with transference. some therapists are simply too uncomfortable, not well-equipped, and in extreme cases use it to take advantage over a client. personally, i have experienced transference to be both harmful and helpful, with different therapists. one was sick in his own mind and used my transference to take advantage of me and abuse me sexually. my current therapist uses transference to explore my past, my needs, and works with me through it.
i would suggest a book if i may called When the Past is Present by David Richo.