Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Sound › sync external soundtrack › I second the post that syn
I second the post that syncing audio and video is easy by matching waveforms. I do it all the time using Adobe Premier Pro. A problem you are going to run into is that the sync will drift as the video progresses because the recording clocks of the camera and audio recorder are not the same. A drift of 100 ms is significant and has to be corrected. This can be done by stretching the audio using an application like Adobe Audition.
If there are any dropouts in you audio recording, maintaining sync will be impossible. In my setup I use a firewire connection to the recording PC and I have a lot of problems with dropouts.