Here ya go buddy,
read thisThat should help you with most of what you need. And really, just start searching around the site.
You're right about starting with Caapi/Rue first (of those two I recommend Caapi). And whenever you are ready to start adding the Mimosa, start very very small.. Like 1 gram or less. (Although it would probably be wise to brew more in case you need it, or purge too soon)
As far as brewing, you can do it with cold water if you use enough and wait long enough, but you generally get better results with hot, slightly acidic water. Most people add vinegar or lemon juice. You'll want to bring the water to a simmer, just below boiling.. You can do it in 30 minutes or so, but the more effort you put into it, the more you'll get out of it.. And three rinses of at least 3 hours each is recommended.
Brew the Caapi and Mimosa separately. After the first 3 hours, strain the liquid through a shirt or something into another container, save that, and then add more acidified water to the plant material and repeat the process two more times. When you're all done, you can simmer the liquid you've collected for awhile to reduce it. Drink the Caapi first and wait at least 10 minutes or so.
Of course, there are many ways to do this, and there are many people on this site who have MUCH more experience with this than me, as I've only just begun myself. I suggest you wait to hear from some more people as well. But really, read the "all about aya" thread I linked at the top of this post, it's very informative. Good luck friend!
Embrace this moment, remember: We are eternal. All this pain is an illusion.