My site has horizontal menus. Before the users log in, I want the menus to point to pages like "Home," "About" and "Contact" ; however, after they log in using my custom made login system (which directs users to a different page), I want the menus to point to other pages like "Add a post" "Edit Posts" and "Delete Posts." Is that possible?

Yes this is possible.

In the CMS you can control who can access each page in the access tab of that page.

Set Who can view this page to either Logged-in users or a choose a group with Only these people (choose from list).
These pages won't be viewable and shouldn't appear in the menu for people who aren't logged in.

Hi ampedup, thanks for your response. Is there any way to make a menu visible to only those who are not logged in? I don't think an "about us" or "FAQ" section is necessary for those logged in already, but will be very helpful for those who are deciding whether or not to register for an account. Therefore, I want to get rid of those menus for logged in users. Thanks again!

Damn, that complicates things.

Here is another post about your problem:
http://www.silverstripe.org/data-model-questions/show/266450

If that doesn't help we can try something else.

I read over the post, but didn't really quite understand what banal was talking about. It seems like his code checks whether a user is logged in, admin or not logged in. Based on the status, it will return a Boolean value. How would that be different than, say:

function canView(){
	return (Member::currentUserID()?false:true);
}

Wouldn't this check for whether the user is logged in also?