To edit and add information to the header of the site uses the positions “adress”,"logo","Login".
You can enable your contact with some information such as phone, email, adress on your site.
To use go to Appearance->Widgets.
You can insert any of text or HTML and use the icons for beautiful display your text. Read more about Font Awesome.
Gem template allows you to upload your logo as an image file or use text.
To use go to Appearance->Widgets
If your site requires registration, use the Sidebar Login Widget