Hello Elena,
1.As new to C4C, I will suggest you to logon via Silverlight and click on 'Help Center' and check hyperlink "Help Portal".
=>It will help and gives you detail overview on Whats New/User Guide/Admin Guide etc..
2.Also you can check "Make SAP Hybris Cloud for Customer Better" (Idea Forum) ,which is below 'Help Center' option .
Best Regards,
Ankush Pashine