Adding a linked logo onto your header

Hi guys, quick thanks to all the knowledgeable people that help us less knowledgeable people with our sites.

Can anyone help me, Im trying to add an associated linked logo to my header, anyone know what code I will need please?

I have found the header.php file and can sift my way though the text to where it codes the LinkedIn logo and the company email address and contact telephone number.

I would like a provided logo to the left hand side of the LinkedIn logo above my email address with a linked url to their website. Where abouts will it pull the logo file from ?

Here is the header code:
<header>
<div class=”container”>
<div class=”row”>
<div class=”col-sm-6″>
<div class=”site-logo”>“><img src=”<?php echo get_template_directory_uri()?>/images/logo.png” alt=”DataCenter Logo” ></div>
</div>
<div class=”col-sm-6″>
<div class=”header-info”>
<ul class=”social-icons”>

• <i class=”fa fa-linkedin”></i>

<div class=”contact-details”>
<span class=”phone”>0845 299 6563</span>
[email protected]
</div>
</div>
</div>
</div>
</div>
</header>