Could I get a prerequisite list from the more experienced individuals that is reconmended before trying any of this..

By the way, I'm not intending on invoking demons, preferably my guardian spirit.

^^^I really don't believe in all this stuff, but my roomate does. He wants me to join him in one of his ceremonies to I can "see". Is there any thing I need to fear? Why can't I just tell an entity to fuck off? If I do not fear them won't I beat them?

You have nothing to fear. Fear is your worst enemy. And your roomate is most likely--to use a rather imprecise term--nuts.

Back to topic--read the following:

The Way of the Shaman, by Michael Harner
Plant Spirit medicine by Eliot Cowan
The Power of Intention by Wayne Dyer

By the way, I'm not intending on invoking demons, preferably my guardian spirit.

http://www.llresearch.org/library/a_channeling_handbook_pdf/a_channeling_handbook_pdf.aspx