How to create node and assign user permission automatically

I would like to have 2 nodes created (For a gallerix gallery) automatically when a user registers, one that is a 'public' gallery that anyone can view, and one that is a 'private' gallery that only people that the user specifies can use. So basically I want to know:
1. The best way to have the node created automatically and assign the new user edit access while restricting everyone from viewing the private gallery
2. How to create some kind of 'Friends list' that is configurable by the user that gives the 'friends' permission to view the private gallery