I've finally been able to do some reading on the subject and found a book by Jon Klimo - 'Channeling: Investigations on Receiving Information From Paranormal Sources' that I think is worthwhile reading:
http://www.amazon.com/Channeling-Investigations-Receiving-Information-Paranormal/dp/1556432488/ref=sr_1_4?ie=UTF8&s=books&qid=1218530821&sr=8-4
I'm only a part way through but has opened my eyes to the extent of channeled material that is out there.
It seems many people do not choose(consciously) to channel their higher selves but are rather thrust into contact.
This is what he says about Jane Roberts.
On an early September day in 1963, in her apartment in Elmira, New York, thirty-four-year-old aspiring poet and novelist Jane Roberts first encountered channeling. It was to remain at the center of her life until her death in 1984. As she recalls, it was "as if someone had slipped me an LSD cube on the sly." Having had no more than a couple of fleeting psychic experiences before then, she was overwhelmed by the new phenomenon: "A fantastic avalanche of radical, new ideas burst into my head with tremendous force, as if my skull where some sort of receiving station, turned up to unbearable volume."
She found herself face-to-face with an adjacent level of reality more real than the one she had known:"It was as if the physical world were really tissue-paper thin, hiding infinite dimensions of reality, and I was suddenly flung through the tissue paper with a huge ripping sound. My body sat at the table, my hands furiously scribbling down the words and ideas that flashed through my head." Her ideas about the nature of reality were turned upside down, as more than one hundred pages of a manuscript titled The Physical Universe as Idea Construction poured forth onto paper:
There are countless examples of similiar situations. This intrigued me as it appears some are a 'kind of offshoot of a higher group'(for lack of better English) and regardless of what they consciously choose to do end up meeting their 'higher selves'.
It also seems(as would be expected I guess) that the limitations we bring to the channeled experience determine what one gets out of it:
Ken Carey writes of the channeling experience
The messages came first in non-verbal form, on waves or pulsations, that carried the concise symbolic content of what I term "meta-conceptual information". Automatically, it would seem, the nearest approximating words or phrases from the English language would be assigned to ride, as it were, the fluctuations of the non-verbal communications. Often it was the case that the only human conceptual system with approximating terminology was religious. Hence the occasional use of "Christian" words or phrases...
Other channelers speak of receiving 'impressions' and having the task of translating what was intended into written language.
When asked "What are the limits of your knowledge?" Lazaris answers:
We may not have in your language the same vocabulary words, because we may run into certain vibratory frequencies that have not aligned with in your reality... Therefore we would suggest here that the beginning and end of knowledge is available to us. The limits of our knowledge is really the limits of what a person would deal with. And therefore the question is not so much, "What is the limit of our knowledge," as it is "What's the limit of your knowledge?", and that will define ours.
Jon Klimo also recommends
With the Tongues of Men and Angels by Arthur Hastings as one of the best books regarding the phenomenon of channeling, although I haven't read this one myself.
http://www.amazon.com/Tongues-Men-Angels-Channeling-Institute/dp/0030471648/ref=sr_1_1?ie=UTF8&s=books&qid=1218533533&sr=1-1
Jeff.