In general I think you will find the process a good one. CFI
candidates are normally treated as professionals--and be certain you
act as a professional. Especially if the examiner is a fed dress for
the ocassion--don't need to over do it, but look good. The examiner
will not expect you to know all of the details of flying and the regs.
If you are not certain tell him/her that you want to refresh your
memory by checking the FARS/AIM, etc. That is what they want to see.
Have a good understanding of the regs--and endorsements!
Finally--LISTEN to the examiner. Often if you are straying on a topic
he/she will try to guide you--take the hint!

Good luck--

Skip Guimond