IMDB
OK grandmother, I'm going to introduce you to the art of egg-sucking. Yes, obviously you know about IMDB. Here's something worth understanding, though: IMDB is now so ubiquitous and authoritative that it has become the de facto reference to the industry. In the real world, the one we all try to escape through writing, your IMDB credits are your professional CV.
BoxOffice Mojo
Writers, like generals, are obsessed with advances and retreats. The industry also contains strange people who care about money. These people always drive better cars than us. BoxOffice Mojo simply provides the details of how much money a film has taken over the counter. Not only does that matter to the producer, it also matters to the next producer who hires you.
Calendars
A set of quick links to upcoming dates for those interested in film.
Film releases
IMDB Release Calendar
Sortable by country, this is the release-date of every upcoming movie.
Events
IMDB Events List
Pretty much every professional film festival and major event is in this list, courtesy of the lovely IMDB people.
Festival submissions - Withoutabox
Withoutabox
Withoutabox is a tool for online submission of films to film festivals. It only features festivals that it serves, but it's a pretty good list.
Specialist screenwriting software
Final Draft
Final Draft is the traditional standard software for screenwriting. Entire generations of screenwriters have written and rewritten using its weird but comfortable interface. It's biased heavily towards the way the industry has always worked and its collection of tools, templates and collaboration components have always felt like an afterthought. What it does best, better than any other software, is identify you as someone who is willing to come and meet the industry on their own terrain. Go to their homepage and you'll find the logo of every single MPAA studio, or their parent. For those who care more for quantity than quality, and I pity you, it's also claimed to be the top seller. If my own experience is anything you care about, and if so I pity you even more, then let me point out that it's the software I use for screenwriting. Final Draft have never offered me a free copy, discount or any inducement to mention this, I just love the software.
Movie Magic Screenwriter
If there's one serious competitor to Final Draft it's this. The interface is very similar and the use of simple tabbing and entering between different formats is essentially identical. Some people tell me it's better, some tell me it's cheaper. Certainly it's part of a wider family of software for outlining and defining your project, most of it under the Dramatica label. Proponents point out that MMS has won a technical Academy Award and that the WGA West endorses it. Actually they only endorse the file format and they're an organisation of writers so they'll endorse pretty much anything if you give them a bottle of cheap Scotch in return. Joking aside, I'm only a little familiar with it, but I have confidence that it will do the job.
Practical Scriptwriter
Modestly priced with free upgrades, this one is starting to be mentioned wherever writers pull on their robes and cluster around the altars of the screenwriting gods, chanting "Nobody knows anything" as they sacrifice reams of pristine paper to the ghost of Joseph Campbell. Wow, that sentence got away from me a bit. Not a serious competitor to the big names, lacking the mass collaboration, version control and toolkits they offer, it is a clean, easy to use, package for getting format right. Ultimately, this is an excellent basic system.
Page2Stage
Now free, Page2Stage used to be commercial software. If you find a site that still sells it they're pulling a fast one. Undeniably a fairly simple script editor P2S nonetheless works fairly well and is certainly priced to move. For those poor benighted souls who've slipped from the path of Wintel rectitude, you'll need a VM or similar, this one only speaks Windows.
Content-based writing software
Scrivener
Scrivener is essentially a highly enhanced text editor. I bet you always wanted one of those, right? Well, before you move on, let me try to explain why it might be a thing. In the Scrivener world a project is made up of files, these files are essentially text, they can be swapped around, modified and when the finished thing makes you happy, compiled into whatever format you need. One of the potential formats is, obviously, a screenplay and you can modify it to your heart's content, but it's also brilliant as a structure tool during story development, punting out Kindle-ready eBooks or manuscript-ready novels. Aside from Final Draft it is the only writing software I pay for and it's probably the best value software on my computer.
Celtx
Celtx is the brand-name of a series of products that have steadily migrated from standalone packages to web components. The software makes bold claims, suggesting it can handle everything from outlining and content structure through to storyboarding, budgeting, script formatting and, possibly, driving you to set each morning. It's been a few versions since I used it but certainly back then it didn't do any of those things. It was incapable of correctly importing files even as complex as simple text without messing up the layout, its supporting content structure was laughable and its output was only vaguely similar to professional packages. On the other hand it was free. Now it's not free, rests on a client-server model making it less useful, and has many improvements. Me? I wouldn't.
The first workshop in the Introduction to Screenwriting Resources