Here at AWSOM.org I try to keep things as simple as possible in terms of how I set up my plugins and tutorials for WordPress. I have to be honest though, someone has beat me in the simple department. A new plugin for Firefox/Wordpress has made it exceptionally simple to upload a new plugin or theme to your WordPress install. OneClick is a plugin that literally makes it as simple as clicking a link to add a new theme or plugin to your install. It seems to work like a dedicated ftp program that you set once to your install and then it just works. It even has it’s own plugin/theme backup system! If you want absolutely simple this is about good as it gets.