I donÂ´t know how much time you have to do the project, but HOW you do it depends on how serious you are and if you want to learn anything…nobody can do this for you.
First of all Adobe Premiere is excellent software…learn to use it. I suggest you get a buddy who has a few clues about it or someone who has used it…a quick personal tutorial should get you started. Otherwise look for online tutorials…try google with something like “adobe premiere tutorial”…
Hopefully you already have a computer and LOTS of HD space. You will also need a lot of time…some stages of working with videos requires more time than you might expect…particularly a stage called “rendering”…it may run on some machines for 20 minutes and on others overnight (obviously also depending on how much data your video contains).
As for the trailer itself…my favorite is the trailer made for the first SAW movie. http://www.youtube.com/watch?v=RTUc1SjsT3c Actually it wasnÂ´t the final trailer…rather it was the short promo film James Wan made when he finished film school to show potential producers (sometimes called “SAW 0.5”)…it certainly worked. He got a pile of money to make his first feature film…which went on to become highly successful. Pay attention to things people like this do. View lots of trailers…check out YouTube.