Dear Meditator,
Absolutely Yogani's book and a clear understanding of witnessing / inner silence and so on is useful. This will put the whole process into the correct context. Unfortunately some modern teachings present Jnana Yoga out of the right context, leading to confusion and adopting mental algorithms, beliefs, and identifying with inflexible mental positions, all of which can be incredibly destructive to your growth and engagement with life.
My advice on this subject is as follows:
1. Meditative explorations and inquiries, that use a combination of Jnana Yoga type reasoning and self inquiry, combined with inner stillness, and hence take you beyond thought, are more productive than cold-reasoning. Deep inner stillness is a pre-requisite for effective self-inquiry.
Here is an excellent two part Jnana style guided meditation by Adyashanti:
http://www.youtube.com/watch?v=lCrWn_NueUghttp://www.youtube.com/watch?v=783Gb4KbzGY2. A living teacher is ideal to guide one on this path. Ramana and Nisargadatta were great, but they weren't user friendly. There are just recorded talks by their devotees. If only they'd written books designed to be an easy and user-friendly approach to Jnana, easily accessible to all - like AYP! ;-) Living teachers who present very clearly are Rupert Spira (he's best listened to or watched on youtube) and Greg Goode (Standing As Awareness and The Direct Path : A User Guide are good ones).
3. Liberation Unleashed (.com) is quite good. But tread with care. There's so much rubbish neo-advaita spouted about on there by people who are supposedly 'liberated'. A lot of people taking fixed mental positions. The overall sense I get from LU is there's a trend in their community, rather than taking an active role in growing, evolving, dissolving old conditioning and blocks and using spiritual practices to take ourselves beyond the confines of our old, limited and worn-out self-centered ego consciousness, they'd rather just hunker down in fixed mental positions like 'there is no dooer' and 'there's nothing to do' and 'i'm already liberated' or whatever. There's a tendency to just mentally negate everything, rather than follow the guidance of the heart. People stuck in their minds, basically. It's sad and could be a trap for someone who doesn't have the right context for Jnana.
I hope that is helpful.
Love,
Josh