I was filing through some of the posts and noticed that the structure of the head tag is pretty important. I know that doctype and charset is first and foremost, but is there a science to organizing the head? (local css, local js, external css, external js, meta tags) My thought process is that you should link local files last since they will render the quickest and the external scripts and styles first since they require more tome to render?
Not really a problem, just acquiring knowledge.
You might want to Google for boilerplates like html5 boilerplate, Twitter Bootstrap, Goldilocks Approach and probably many more and see how they organize the head.
It is also good if you can minimize the amount of requests, although if you have stuff that you can cache to far distant future (this can be done via htaccess/server configuration) then it isn’t that bad even if you have a few more than what some consider “ideal”, that is only have one (massive) stylesheet and one (gigantic) JS.
If you setup a long cache time and still want to do modifications to the CSS and JS files and don’t want to constantly keep on changing filenames there is one trick you can do:
Adding the last modification date like this is a good idea as just changing that is enough to force browser cache to reload the script when the modification date is changed. Setting up PHP code to output this information is simple enough.