I already use aMember but I would now like to switch my site to drupal. I want non-members to be able to navigate the drupal site without logging in or signing up...only when they click for a pdf file would they be prompted to log in. I have that working fine on my current site as only my /pdf/ folder is password protected with aMember. Is it just as easy once I use the drupal plug-in??
You need it only if you want to protect content inside drupal. If this is not necessary, plugin is not required then.
but how would drupal username/pw and amember username/pw function together? I would imagine, if I didn't have the drupal plug-in, they couldn't. if a user wants to navigate around my drupal site, they will need to sign up with a drupal account. Then, if they click on protected files, they'll be prompted to sign up for an amember account. If these aren't kept together (which I presume the plug-in will do) it will be very confusing having two log-ins needed. It's very possible I haven't really understood the whole concept of drupal and amember together.
Of course you will need plugin if you want to sync users between aMember and Drupal. In last post I though that Drupal registration/login system will not be used. If you will use it Drupal plugin will be required.