There's a lot of programs you can use to put video clips together to make a movie. Some automatically come with your computer/laptop, like Windows Movie Maker. (although note that the versions are different depending on what Windows version you have) This program is simple and easy to use, but it's not the best. iMovie is a step up, and comes with the Mac, but you can download it too. There's also Sony Vegas Premiere or Pro, (more advanced program) Adobe Premiere Elements, (I have this program and it's absolutely amazing) and finally, Final Cut Pro, a proffesional editing program. It's what filmers use to make movies and pretty expensive. My advice to you is based on what videos you are going to upload, you should think about what effects you would want to add to it, how complex you want your videos to be, and judge it from there what program suits you best. Remember, don't choose one that you think might be too hard for you to use, practice with the one you get, and then once your better at editing, move it up one level. I hope this helped and good luck posting!