A small doubt about Face Book guys , continue reading :

i think it depends on their individual notification settings, but they will all be able to see if they manually go onto the page without being notified. Hope that helped.

ya. all the members of your group and connected people will be able to see it unless you change the options to make it private.

Well, if it is a group, I think you will be link to all the members. That is how members are communicated with each other. It is a group so this may be the likely way to do, if is a personal, then it is you and your friend alone. You see the logical I put forward to you here. I really do not know how it works, but this is seems to be the logical explaination to me anyway. Good luck.

I am not a prolific user of facebook but I do know that everyone sees everything they want to on facebook. While it is a good site for finding old acquaintences and keeping in contact with family, there is not much privacy there. I could be wrong in my limited experience but I don't think I am.

The notification will say "(your name) created a post in (group name)". So basically, the 300 members will be notified. Now, it's up to those members if they will look in your post / link, because sometimes even with notifications, they procrastinate in checking it out.

all member of the group will get noticed in facebook as well as through the mail. This is bad! If you post in chat it will too appear to all