Upgrading is as easy as it could!
You have several ways to upgrade your installation:
1.- Install the new version as a new installation: This option is the "best" except one BIG problem, your data will not be available in a easy way.
I will NOT recommend this.
2.- Manually upgrading: Download a new version, copy all the files from the package with the ones in you installation. An upgrade.sql file could be provided if there's any change at database level. (Note: some files could be added, which didn't exist in your previous installation, also, some files could be no more needed).
3.- Use the auto-upgrade system (already included in OSClass, I think we included it in 1.0). The auto-upgrade feature will download a new version, copy new files, erase files, upgrade your database,...
The auto-upgrade feature will inform you if a new version is released, and should upgrade your system to 1.1 release (we have to prepare the auto-upgrade pack yet). It will only upgrade to stable releases (1.0, 1.1, 1.2, ...)
Versions name as alpha/beta/gamma/delta/release candidate are "development" versions. We fix errors, we include new features and they "should" be stable, but we don't recommend them as a production site (ie. if your site is already public). After the release candidate, we stop adding new features and we focus on fixing the errors, to make it as stable as posible. Auto-upgrade will also inform you if a "hot-fix" version is release (ie. some security error or a serious bug is found, a patch version will be released as soon as posible).