If you need, besides major accounts, an extra account with limited access to data, you can add Windows 8 Guest account. The process is almost the same as in Windows 7.
Google by far isn't only a search service or an e-mail provider. I will introduce you to their Google Docs service which you can use as your very own office in the cloud.
If you are a "private" person and don't want your profile picture or name to appear on your friend's feed next to ads you liked, then follow this steps.
To avoid using someone else's copyright protected images you aren't allowed to use for commercial or even personal use, Google Advanced Image Search has got you covered.