I'm generally against just posting a link to a site without some useful commentary (i.e. add more than just "check this out"), but in this case the site http://www.filmsound.org is so good that it warrants a link on its own. More so, it warrants a permanent banner on the site. No matter how experienced you are (or how good you think you are), you will find something new to you on the site. Before asking questions on any site about how a sound effect was made or how the overall sound was designed for a blockbuster movie, read the articles on http://www.filmsound.org