Upgrading Plone may be a simple or a difficult task dependengin on how much customized was your installation. More information would be nice: is it already in windows, or is it in Linux and you need to migrate to windows? Do you have any idea if your old Plone installation (3.3rc5) has lot's of custom addons or not? Do you want just to migrate the data from default content-types, or do you need to migrate plugins and such?
These are first steps to know how we can help you. Then, you can follow the docs from Plone Upgrade Guide — Plone Documentation v4.3.
Also I cant seem to find some clear documentation on how to install Plone 4.something and I can't find binary installer?
Indeed, this is not explicitly stated on the official website, but only here in the forums. https://plone.org/download/releases/4.3.1 doesn't exist anymore but you can download from 4.3.1 : Plone and follow the instructions in Cannot find windows installer or another approach as defined in Cannot find windows installer - #4 by cdw9.
@tkimnguyen can we improve the official plone.org? An example: in frontpage, when you click in "older releases" it goes to launchpad, but in download section that's a button for Plone 4 that stays in plone.org. Why this difference? Shouldn't this interface be the same?