For starters, us.imdb.com is pretty much THE WEBSITE for film information.
Filmsite.org is a non-profit site which is a virtual encyclopedia of film. It has a wide collection here of various compilations of the best films ever made:
79 Best Pictures is a project of two people (boyfriend and girlfriend) from the University of Maryland who plan to watch every Oscar selected for best picture over the course of a year
Turner Classic Movies has a great database which has a more thorough synopsis of a film than you'll find on the imdb.com. If you want to skip straight to the ending
Box office mojo is a great source for facts and figures from the box office and is pretty much the definitive database for box office stats. You can also play a game where you try to successfully predict the box office intake
One of the best magazines that I used to read on the film industry crumbled recently and now it only available online, there are here:
If you're looking for goofs on movies, there's a fun one called
There are about a million other ones too