Now that you've seen it, you might be wondering, "who the heck is 'Star-Lord'?" He's been around for a while - and a while back I took a look at the character's history and talked to some of the folks who wrote him over the years. You can read those articles over at Comic Related:
Part One: http://comicrelated.com/news/17021/star-lord-part-1
Part Two: http://comicrelated.com/news/17937/star-lord-part-2
Part Three: http://comicrelated.com/news/18390/star-lord-part-3
These were written back when the movie was first announced, so some of my references are a little dated. But if you're curious about the character this will fill you in!