Timing of script pages (I'm making a short film with a friend, and we want to make this as close as possible to a blockbuster film without blowing our budget. We have spent about $5000 on a camera, lenses and two microphones. So we have made an outline of the movie and I've started making the script. I'm using Final Draft 8.)

I've written the first page which describes what happens when the actors and our names appear in the beginning of the movie and the start of the first scene. I figured that all this lasts exactly 1 minute, and the page is only 3/4 full. Should I expand the page, should I start on a new page or should I just continue and end up with a page describing 1.5 minutes?

(Do you know about a good website where you can learn all you need about this stuff? All the websites seems to have their own interpretation about how you should write a script. Some make them for Word, WordPad and so on.. As I said, I use Final Draft 8.)
As a rough estimate, one page of a script equates to one minute of screen time. It is impossible to say exactly how long a page will last on screen because it relies on too many factors. 

You shouldn't worry about trying to make each page go for exactly one minute. You'll find that some pages will go over a minute on screen and some will go under. So don't start a new page - that'd be incorrect script formatting and if you give an incorrectly formatted script to a producer you'll have no hope of getting it made. 

I've found the best way to learn how to write screenplays (other than professional lessons) is to read screenplays. Here are a few websites that you can find scripts on:

Drew's Script-O-Rama

Screenplays for You

Simply Scripts

Daily Script

I haven't used Final Draft to write scripts before. I use Celtx and it's an amazing program. It's free and it formats the script for you as you go. I highly recommend it.