I'm busy writing my first plugin, using PHP 5.3.5. I come from a C# environment, and I must say I'm more than happy with the level of support for good, solid OOP techniques in PHP. However, I'm a little uncertain how to structure a plugin using classes. I have a plugin class that takes care of hook registration in its constructor, and some worker classes like a mail queue and mailer, but I have one or two non-class scripts, mostly for forms, that I don't quite know how to neatly fit into classes. What resources are their I can consult for guidance on this aspect of my OO plugin?
The plugin is for mass mailing, i.e. mailing to all subscribers, on schedule etc. It registers a custom post type for mail templates, with add new and edit capabilities, and it adds its own menu to the bottom of the admin menu, currently with two submenu pages: 'settings' and 'send mail'. It also adds an 'opt out' option to the user profile page, but that's quite tidy and easy to include the main plugin class.