I don't know much about anagariking in the west....I guess you will be at one particular temple...if this is correct then to prepare I suggest going there every month for the special "Buddha day" (that's what the Thai people call it, i don't know the Pali or English terms for it) and wear white and follow the 8 precepts and help out with whatever they do on that special day.......while doing this you could mention that you are considering anagariking there and are wondering how it works.....you should be able to get your questions answered and get a small taste of what life would be like....
Coming from another direction entirely I think it would be good to read, study, and contemplate the Ariya-vamsa Sutta:http://www.accesstoinsight.org/tipitaka ... .than.html
AN 4.28 PTS: A ii 27
Ariya-vamsa Sutta: The Discourse on the Traditions of the Noble Ones
translated from the Pali by
The Buddha declared that he was of the lineage of the noble ones and that he followed the tradition of the noble ones.....this sutta say that there are "These four traditions of the Noble Ones — original, long-standing, traditional, ancient, unadulterated, unadulterated from the beginning — are not open to suspicion, will never be open to suspicion, and are unfaulted by knowledgeable contemplatives and priests. Which four?"
And to summarize the four:
1. Any old robe at all will do.
2. Any old almsfood at all will do.
3. Any old lodging at all will do.
4.Finding pleasure and delight in developing (skillful mental qualities), finding pleasure and delight in abandoning (unskillful mental qualities).
I think internalizing these four will be your best preparation for either anagariking or even for just remaining in the lay world.