It is probably best to say that the more "upmarket" you go, the more tools you get to do the job.
Again I will talk about VideoStudio Pro and Pinnacle Studio (both now sold by Corel) as they are the only ones I know.
First you can mix video and stills on the same timeline. You have lots of "transitions" i.e. wipes, fades, starbursts etc. to move from one shot to the next. You have overlay timelines to set up "cutaways". You have picture in picture and chroma key (greenscreen), loads of effects and so on. More important you have good control over your pictures for brightness, contrast and colour and your sound. There are four audio channels plus a voice over channel. They are like Windows Moviemaker but a lot more powerful.
I bought the Ultimate version of VideoStudio Pro X6, this has extra third party programmes attached. For example, Mercalli which is a shot stabiliser to remove shake from a handheld shot. (incidentally V700 has a really good optical stabiliser built in and - boy do I need it!!) It also has a thing called RotoPen which can be used to trace a route on a map or highlight an object.
Best thing is to go to the Corel website and be amazed by their advertising waffle.
If you go for the V-700, Panasonic include software called HDWriter. This has an editor built in, I have never used it as I only use HDWriter to download the video and stills from the SD card.
To be honest I only use the editor to string together family videos and documentaries of my local area so I don't use a lot of the vast range of "extras". I have used Chroma Key and a range of the transitions. i also use the ability to "stretch" audio to fit a video shot. Example: I download a track from a CD roughly the same time length as the video (and appropriate music!) and I can stretch or compress it to fit the picture. This action will affect the speed of the music but not the pitch as the music is digital.
If you do look at the VideoStudio web page, click on to the Compare Versions (PDF) and you see what your money buys. Also the Getting Started guide, it gives you a good idea of what is available.
If Windows MovieMaker is a little run around then VideoStudio is a Ferrari. ( Perhaps you will think a run around is far more sensible)