If you want to build a website with access to specific content for specific users, you can install S2 Member. S2 Member will allow you to create custom roles and capabilities. Then, you can restrict access to content (pages, posts, etc…) based on these roles and capabilities. On the other end, you can grant specific roles and capabilities to your users.
You can make your user pay via Paypal to access the restricted content. This is a good way to generate revenues from your blog.
WordPress plugin advisor 