I am a complete noob to programming and CakePHP all together, so please be patient. How am I supposed to call the CSS on this Html->link:
Not sure what you mean by "call the css", I think you want to add a class to this link? IF that's the case you can just add another array as an argument and it will turn key =? value into HTML attributes. EG:
echo $this->Html->link(__('Blogs', true), array('controller' => 'posts', 'action' => 'index'), array('class' => 'my-class'));
This is all explained in the CakePHP docs.