Edit a video

We have create a script and also created a video based on that script. We used a screen capture tool named JING to create the video. It has 3 parts now and they need to be merged to create one single video. We need someone from the USA or UK to add a voice to this video according to our script. The video has been created but there is no voice right now. Should be an easy job for someone who has a basic video editing knowledge. Thanks.