Suggest first download each cassette (as a separate file) from the camcorder onto hard disc, using Windows Movie Maker's built-in 'Capture Video' options.
Then use WMM to edit to your heart's content! Each file can be edited separately, and/or combined with one of more of the others, or whatever.
For eventual burning to DVD, save the composite file(s) in DV(AVI) format.
Note that, with a lot of source video, it can take a //long// time to transcode it into to a format suitable for DVD-burning. You could be talking many hours...
Some versions of WMM will allow you to burn to DVD(s) directly. If not, use third-party software such as Nero or freebies from (for example) click here in the 'CD & DVD Tools' section. HTH.