I am an iPhone mod noob. I have no idea how to mod or understand anything. The best I can do is follow instructions.

But before I start I'm really "scared" of all the iphoen "bricking" and errors that other people receive. HOw do i prevent these errors? What are some steps to avoid that will surely "brick" or make your iphone not operating at 100% it was intended too

Are any of these true?

1) If you downgrade to 1. 02 you cannot use the phone, wifi ?
2) if you upgrade from 1.02 to 1.1.1 your phone gets bricked?