For the WSUS server, proxy has to be configured if WSUS needs to use a proxy server to have Internet access
WSUS is used for automatic downloads of updates, hotfixes, service packs, and device drivers
For the Windows 8 clients, using a Domain GPO, Configure Automatic updates to do one of the following: Notify for download and notify for install, or Auto download and notify for install, or Auto download and schedule the install or Allow local admin to choose setting.
For the WSUS server, updates must be configured to specify the way this server will obtain updates (from Microsoft Update or from another WSUS server).
For the WSUS server, firewall exceptions need to be configured if WSUS is behind a corporate firewall