Between 2009 - 2015 I spent time on a project to offer mountain bike tours in Georgia called Georiders. I didn't get around to creating these videos from some of the footage shot, mainly because I found there wasn't a bit of software out there that just let me create little videos on the fly. GoPro's studio software is available as a free download and you can use it to edit not only GoPro footage but footage filmed with other devices.
If your footage doesn't import properly you can also use software called Handbrake to change the format. I'm no professional filmmaker but I it annoys me having footage kicking around on a harddrive with nothing done to it. Here are a couple of edits of footage shot mountain biking in Georgia in 2014/2015 running tours and riding the local trails.