The first thing you want to have is a designated folder for your video files. If you like to record a lot of video, then you would be surprised to learn just how much space it takes up over time and how quickly it can get out of hand for you to try to keep track of your files. For individual video projects you will want to create sub-folders and organize them either by date or by specific project titles. This will also make it easier to pull any videos for further edits.
On the technical side of the GoPro video editing process you want to be sure to have a dedicated video editor. If you are stuck using Windows Movie Maker then you will definitely want to download the free GoPro Studio Edit Software. This program natively handles GoPro video files without the need for conversion so you can put your footage straight into the program. Under normal circumstances Windows Movie Maker would be adequate but GoPro footage is a step above simple home movies so using a more upscale editing program will help you get the best out of your footage.
As for the manner in which you edit it, some basic tips would be to edit out the first and last few moments of your video. There is nothing really compelling about those first few moments where you turn your camera on and those last few moments where you turned it off. You want to really be sure that your footage is enthralling, so any parts that do not seem exciting should go. If you are going to put music in your video and you have a piece of footage that has a singular stand out moment then you want to use music that has tension and then release. This is why you will often hear dubstep used in GoPro videos as many editors like to punctuate the stand out moment with the bass drop. Ultimately you should edit your video in a way that you find pleasing.