2 users see all files

Hi, I am on a business vacation and am putting the pictures on my serverusing my username, user1. I want my friends to be able to see these pictures which are on the server. What I have done is selected a username for them, user2, and put them in a group called user12. I have no experience in this stuff so if someone could explain how I would get this done, it would be much appreciated. I sent an email to the support team, and they were a lot of help, but i just don’t seem to get it. Throw all security out the window, i want that username to have all access to the server just as I do, or maybe just a folder called Shared or something. Basically, what I need is for them to log on to my server using user2 and default into the shared folder and have read and write access. I want to be able to dump photos in that folder and have them see them, and let them put files in there as well. I am using the terminal/cyberduck om my mac, and they would all be using Windows. I have also set both users to a shell account type, just in case. Thanks so much!