Basic info? eh...I don't really know what to tell you.  Try to relax, and just let go.  It'll be unlike anything you've ever experienced, but if you've done psychedelics a fair amount, you should have no problem.  If you feel yourself start to panic try just closing your eyes, and taking deep breaths.  I find it far less anxious with eyes closed, probably because everything around you changes so fast, it's kind of unsettling.  Or you can try just staring at one thing till you calm down.  That seems to work too, especially if you feel like it's too much too fast.  Just take in a little at a time.  Pick one thing and focus on it.    Don't put the flame directly to it.  Hold the smoke in as long as you can (or just 20-30 seconds).  Do it somewhere comfortable, be safe, don't drive, have fun etc.  Hope that helps.