Hi Freebird,
Film screenplay layout is a bit different from television formatting.
There are some places online where you can read scripts, for example:
http://www.script-o-rama.com/
You can learn about format from reading them. You can also read some good screenplays and some less good screenplays. You can figure out what you like.
Timing wise, the rule is one page = one minute. Getting layout right and not trying to cram too much on a page is important. Otherwise the production won't be able to predict correctly how long the film is going to be. Average feature film scripts are 80-120 pages. Shorter in Europe, longer in the USA.
Good luck,
Kate