It would be nice to put a message that newbies can't post in the top of the page

[ronenfe]

or in an alert, or a private message in the inbox.

After trying to find how to post for  a while,
I had to search the web to find why i can't post here.

[20max13]

or in an alert, or a private message in the inbox.

After trying to find how to post for  a while,
I had to search the web to find why i can't post here.

Well you managed to figure it out, I'm sure others can too

[DannyHamilton]

or in an alert, or a private message in the inbox.
- snip -

It would be a waste of effort.  Anyone who doesn't notice this message while creating an account isn't going to notice the additional messages:

[ronenfe]

I am sure many would give up, it took me an effort.
It's the first time i see such thing, usually you get a verification email, which allows you to post after that.

how should people know they have to go to the newbie forum in the first place?

well nobody reads the registration terms 

[DannyHamilton]

- snip -
well nobody reads the registration terms 

Those who don't bother reading the "important information about the forum" message provided at signup, aren't going to bother reading any of those other sources you mention either.  They'll either figure it out, or they will go away.  If they are too oblivious to see the message provided in the signup screen AND too distracted to see the topic pinned to the top of the Newbie Forum AND to lazy to try figuring out where they can post, then they probably weren't going to ever contribute much of value anyhow.

[ronenfe]

I didn't even know there is a newbie forum. i entered the forum where I wanted to post.

[DannyHamilton]

I didn't even know there is a newbie forum. i entered the forum where I wanted to post.

This doesn't surprise me.