It really comes down to trust and self confidence. You have to trust that you're pictures will be received in a respectful manner, which we assure you they will, and have the self confidence to psot them. It's interesting really, you post them the first time with some anxiety, but the results ultimately boost your confidence and lead you to often post more.
As for hosting the pictures, you can attach them in the thread under the "advanced reply" screen, and only those with access to that thread will ever see them. There's a sticky about it in Exhibition.
Hope some of that helps!