Sony Vegas Pro might be expensive, but you probably don´t need that anyways. Sony Movie Studio costs less then 40€ in the basic version and 60€ in the Platinum version, which should be enough for most things you are planing to do. You can get a trial and comparisson of the versions on their website. http://www.sonycreativesoftware.com/moviestudio/compare
would be a good Option @Johannes Kunkel. @Primaguida i think this could be good for starting up making videos.. 720p should also be enough if you don't have a good internet connection