Where one should start learning Mandarim, pinyin or RTH?

Hello, I'm a long time Japanese student, I've did the classic RTK+sentence method and now I want to start learning Chinese. Following that logic I should start doing RTH straight away and then go for sentence mining but, talking to a Chinese friend, he said it was important to learn pinyin first to get the pronunciation right.

So I would like to know which is the path to take for learn Chinese through a sentence method and if I have to learn Pinyin how should I do it?