http://brm.io/jekyll-post-links/
This plugin generates a complete anchor tag with the url and title all pulled from the post. You can optionally change the link text.
Copy the jekyll-post-link.rb file into your _plugins directory.
Usage:
{% post_link post text %}
Where post is a post in the usual date-slug format.
Optional: if specified text is the anchor text, otherwise it's the post title