My issues before installing:
Had some weird old Wordpress install that needed to be uninstalled:
Step One: Delete all "wordpress" folders from the Mac
Step Two: Delete ("drop") all related databases (not tables) from PHPMyAdmin
Step Three: Clear browser cache (maybe not necessary, but why not)
Had been traumatized by previous half-baked WordPress install:
Step One: Consult an actual WordPress book (I chose "Smashing WordPress" 3rd Ed by Hedengren).
Step Two: Read at least three different places in the WordPress codex about installing WordPress locally via MAMP.
Now that my "baggage" had been resolved, I moved onto the actual re-install.

Step Two: Download WordPress.
Step Three: Copy and paste the downloaded "wordpress" folder into your designated folder that MAMP is using.
OK. Seems easy enough. At this point, I pointed my browser to localhost and of course it didn't work automatically. Instead, it complained about my lack of wp-config file.
Now, me and the config file go waaay back. So I felt prepared to make the following changes:
Step One: Open the provided wp-config-sample.php files and change all the DB_NAME settings to whatever is easiest for you to remember.
// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define('DB_NAME', 'database name');
/** MySQL database username */
define('DB_USER', 'yourname');
/** MySQL database password */
define('DB_PASSWORD', 'password');
/** MySQL hostname */
define('DB_HOST', 'localhost');
/** Database Charset to use in creating database tables. */
define('DB_CHARSET', 'utf8');
/** The Database Collate type. Don't change this if in doubt. */
define('DB_COLLATE', '');
Step Two: Go to PHPMyAdmin. Create a new database with the same name you just put into the config file. Create a user with all privileges whose username and password matches the config file. Make sure the user's host is "localhost" specifically.

Step Three: Copy and paste new values from the api.wordpress.org secret key salt page into config (not necessary for security on a local site, but since this will eventually go live, again, why not?).
Step Four: Change the name of the file to wp-config.php and save.
At this point I pointed my browser to http://localhost:8888/wordpress/wp-admin/install.php and lo and behold, it now prompted me to create my user account and name the site! Woot woot!