Windows 8 supports HomeGroups, so you can also connect your PC to the Windows Homegroup, provided you know the password. Homegroup settings, including entering or changing the HomeGroup password, reside in PC Settings. Press Windows-C and select Settings, and then select Change PC Settings and navigate to the HomeGroup menu entry.
Note that you may have been asked to connect to the HomeGroup during the Windows setup. If you've taken care of that chore already, then you're good to go. But this screen is also handy for changing sharing settings.
User management in Windows 8 works similarly to the way it did in Windows 7. However, you now have two ways to manage users. The old way, through the user Control Panel, still exists. Remember, getting to the Control Panel is easy: Press Windows-X to bring up the Simple Start menu and click on the Control Panel menu entry. There's one new entry in the legacy Control Panel user-account-management screen, however.
The top clickable item under "Make changes to your account" is "Make changes to my account in PC settings." Clicking this item takes you to the Windows 8 version of user management. You can also access the Windows 8-centric user-management screen directly. Bring up the Charms bar, select Change PC Settings, and click on the Users menu entry.
Note that the system illustrated in this example is currently set up as a local account. One of the options in this screen (that's not present in the legacy User control panel) is "Switch to a Microsoft account." If you're a home PC user, you may not want to choose this, since you'll always be prompted for your Microsoft account login when you first start up your PC. But there are benefits to having a Microsoft account.
If you add Microsoft account sign-on after installing Windows 8, you'll be asked to supply your Microsoft login information.
Note that if you don't have a Microsoft account, you can click on the Sign up for a new email address link at the bottom, which will launch a browser where you can create both an account and a Hotmail address. However, you don't need to use the Hotmail address as your account ID. I use my personal (non-Hotmail) email account as my Microsoft account login.
You'll also be asked to verify whether the PC you're connecting to your account is trusted. You'll get either an email or an SMS text message (depending on how you configure your Microsoft account) asking you to verify this system. You only need to do this step once.