If you’re familiar with WordPress and want to turn a new or existing site into a membership site, then the sensible solution is to make use of WordPress membership plugins. While there are many kinds of WordPress membership plugins, here are some that I have found to be recommended time and time again:
Easy PayPal – make money from your blog by requiring subscription payments for users who want to view premium content (great if you’d like to save exclusive deals on aircraft parts & supplies for paying members only!)
Member Wing – create a membership site by using an easy “marker”, and allow users access accordingly depending upon the user group they’ve been placed in
Members Only – make your blog visible only to viewers who are logged in; you can also protect your RSS feeds!
WP Members – restrict content to registered site members only
Your Members – create a fully functional members-only site and integrated it with PayPal