I mainly use Windows Movie Maker to capture and edit video. This should be a freebie with most (recent) systems. There's also a load of extras for credits and transitions available from MSN.com. I've tried a few others but keep coming back to Movie Maker.
Once you''ve got the clip/s ready you'll need the usual software (Nero/Roxio) to burn the disc if you want it on DVD.
Avid free DV is very good for the money. You may suffer with hardware compatibility using avid free DV though. I've never yet got it to work with a camcoder. I used to work with and support avid editing suites for broadcasting so I'm not a numpty with this stuff (I hope). The good news is you can drag and drop the video as a file from the camera or SD card. You then import it into freedv if it'll run. Once you know your way around it it's good software. Makes me feel like I still get to play on media composer.
If not use windows movie maker. It's easy to use but a bit pants. Even basic rendering like a cross fade between shots is appalling with bad pixelation. It's not as important with an ATC2K as the piccies aren't high res to start with. Even using my cheap camcorder movie maker suffers on the most basic of edits. The free stuff you get with a mac is better but if you wanted to do lots of editing and already have a PC I'd spend the money on premiere elements.