I am planning to visit the Amazon rain forest. Not the touristy places but a real adventure with a private guide (still trying to find out about that but most likely to French Guiana or Suriname, check Andra's answer here).

I am sure it is dangerous for people like me who know nothing about rain forests (I live in the middle of a desert). I am sure there are dangerous animals, bugs and plants and other stuff I can't think of.

What things I should know about before going there? I want to be well prepared. That includes knowledge and equipment...etc.