How to capture video from devices?

That depends on many factors. What kinds of outputs do those devices have? Look around online for video capture devices which take those as inputs. For instance my Canopus ADVC-50 (I think) takes normal left/right and video inputs that a VCR or DVD player might have as outputs. Some models take S-Video as input, others can take component video, etc. I like my Canopus because it converts the video to DV so I can record and edit it directly in iMovie on my Mac.