This is pretty intermediate in skill level for creating templates. This is to say, in order to be able to create WordPress themes, you need to have a certain familiarity with PHP code. This is one of the many setbacks of WordPress. Never-the-less. They are the most popular CMS engine out there, so if you wish to make it out there creating templates, you better strap in for the learning curve that is coming to you.
Anyways, with WordPress, you can hardcode this right into the head, but it is recommended that dependencies are enqueued into the wp_head() portion of the template. If you do not use wp_head(), then your template will not be able to take advantage of all the features available as a WordPress theme.
Here is a sample of what the enqueuing looks like for LESS.js (Credit to: carlorizzante.com)