First of all let me say best of luck with your project!
Secondly, if you ever need any assistance, feel free to u2u and I will help if I can.
I've worked in the film industry for coming up on 25 years and my concentration has been in Indie films.
I will pass on what my writing prof. said to us in college.
There are three rules of writing;
1. You have to start writing.
2. You have to finish what you write.
3. You have to finish what you write.
As easy as it would seem to throw some words down on a page, writing can be a tedious and laborious process.
Start with your log line as you suggested.
Expand that to a pitch sheet or outline. This should be anywhere from three to ten pages and would be the framework of the story. This is normally
what writers who are looking to get paid to write a script, instead of doing spec work, will memorize and "pitch" to studios to get them to give
them some cash to write the script. Even though you won't be pitching to a studio, you should treat it as such and "pitch" your story to friends
to see if the story makes sense and excites them.
I also would recommend buying a dictaphone of some sort if you can. Nothing is worse than coming up with a great idea and not being able to remember
it. Also, great for long car rides and throwing ideas around in a group as it allows you to go with the creative flow and not have to stop to write
notes every two minutes.
When you feel confident in your outline...dive in.
Try to set aside a specific amount of time and time of day that you can commit to working on it. Think of it as a job and treat as such, even if it
is just an hour every morning.
Try to write a page a day. Not that you have to write a page every-time you sit down, but if you plan on actually writing that day, try to knock off
at least a page.
One page translates into approx. one minute of screen time. Try to keep that in mind if you see you've written fifteen pages of a scene that should
only occupy a couple of minutes. Shoot for a completed script of around 95 to 110 pages. Not to worry if the first couple of drafts are longer, but
the finished project should be somewhere in this range unless you end up writing Lord of the Rings.
Keep going until you are done. Now, take a long nap. Seriously, put it down and leave it for a week. Go back and try to read it with a fresh eye.
If it looks reasonable, you'll want to pass it a round to a few people and see what they think. Take their notes and yours and go back and start
your second round. If you feel it needs more work before you let others see it feel free to go back and tweak it, but don't make yourself crazy.
I've read countless scripts where, when I asked to see the writer's first draft, it was actually better than his tenth draft.
If you can get your hands on it, I would recommend Final Draft for scriptwriting as it is the industry standard. Also, if you are lucky enough to get
that far, it integrates into budgeting and production scheduling software.
Best of Luck,