I'm sure Premiere elements is a good bet for the money, and it also means you don't have to learn new software later when you out grow it and move on to it's bigger brother premiere pro.
Another one to look at is Serif movie plus 4, I believe there is to be a ver 5 coming out soon. The interface is very similar to Sony Vegas. A friend of mine uses it to good effect, and it seems quite stable.
As a beginner there is no reason to spend more than £100 on editing software. All the apps in this price range give you the tools you need (and plenty of naff transistions you really don't) to produce good quality video.
You would do well to read up about camera techniques, as this can really help when it comes to editing, there are many books and websites that can help with this subject.
Good luck.