In term of SEO,

should i always keep directing links to my home page?

or sub pages?

It's highly likely that a large percentage of inbound links will be to your home page, but it is much more valuable, from an SEO perspective, to have a decent amount of inbound links to deeper pages of the website. I don't know if there is a real percentage to the idea, but your content needs to be judged from the entire website's presence, not just links to the home page.

Hope that helps!

You may directly link it to your homepage but linking other pages in your site to others may help too

Link to the most relevant page.

Link to pages that hold direct relevance. In terms of SEO this will hold far more weight than just linking to a home page.....

simple example below :

Im reading a news story on Paris Hamilton going to jail. I can also see a few additional related links on Paris Hamilton, but when I click them, they just take me to another site's home page. I then have to search the second site for the relevant story. NOT GOOD X

Would be far better to link directly to the Paris Hamilton article which relates to the story. GOOD

hope this helps :-)