Hi, In odoo I used to build apps where the admin had to create accounts for other users. 
can you share with me resources to build an app that provides self sign up system with the option to redefine password using email in case the user forgets his password?

Let's Take an example: how to make a registration system like odoo forum.

in the picture below, user can create their own account, without any administrator. Also, the user can log in (which is also provided by odoo) and use forgot password action to recover his password by email