Pinnacle Studio 9, is a "decent" starter. Studio 9 Plus, is a little bit more expensive, but allows you to do more. It's still all cookbook and limits your creativity though. The Pinnacle stuff is prone to crashing at unexpected moments as well.
Studio 10 is out, but I've been reading about various issues that I'm not sure have been resolved as yet. I'll wait to upgrade to that once it gets the bugs worked out.
Sony Vegas 6 is a Professional set up and takes a learning curve. Remember that. It's not the easiest, but once you learn it, it becomes routine. You will also pay more for it. Sony DVD Architect 3 is the companion to Vegas as that's the software where you create your DVD, menus, sub menus, and over all structure. Using Vegas alone, while it probably can be done, is much harder to create a playable DVD. You WILL burn a few coasters!
Here's another thought for the professional software. You can find Pinnacle's Liquid Edition 5.5 at a reasonable cost. Liquid Edition 6 is the current level. There is a lot you can do with the Pinnacle Liquid software, but again, there is a steep learning curve.
Adobe has Premiere Elements, which seems to have some good reviews.
Sony has there Movie Maker (?) based on the Vegas, but is a consumer level series of software.
If you're having sound issues, check your capturing. Some capture software will allow you to "Lock" or "Unlock" the sound track from the video. Other times, your cature may be out of sync all by itself. This can esspecially be true if you are capturing in MPEG2 via USB or even Analog.