When you are ready for video editing system for semi-professional or professional work, you will need the best system possible to prevent downtime and lost work. Many of the good video companies will build systems for you. Called a "turnkey system", they are ready to go right out of the box. If you've got the money it's a good idea. If you don't, read the specs carefully for the video editing software you want (Final Cut Pro, Avid, Adobe Premiere Pro and After Effects) to make sure your system is powerful enough for rendering, ram previews and large video files.