How would I go about redirecting all traffic to the login page? I don't want any guests to be able to view any pages (except signup of course), but instead I need anyone who isn't already logged in to be automatically directed to the login page. I would think this should be a feature within aMember itself, but I wasn't able to find it.
For your main home page simply code it to redirect to login page with something similar to this: PHP: <?php header("Location:your-amember-directory/member/index");?> then anybody arriving at your site would be redirected to login page.
That just redirects to the main Index page, not the login. I suppose I could redirect to "/login" instead. Not the best solution IMO though.
All the other pages are obviously protected (Profile, History, Affiliate, Help Desk), so how would I go about protecting the Index page as well?
What index page do you mean? If you are about your site index page you can set protection this way: http://www.amember.com/docs/Content/PHPScripts
the sites index or default page is the landing page so a simple redirect from there will pass visitors to the login page. ../member/index is what I use to link to login page but use /login instead no problem.