Pinnacle is decent, its taken them a while to build something worth using. Premiere is amazing, but the learning curve on it is something to take into accordance, I went to school for it so I got a leg up on it, but if I were starting off I wouldnt want to use this. To start off with, get familiar with the site doom9.net, it has TONS of great info about encoding, compressing, decompressing, and comparisons of codecs.
Windows Movie Maker is a decent way to start, it'll give you a feel of cutting and arranging data, and adding some bgm, but your encoding features are VERY limited, infact the only options you get are bit rate options, as everything is auto-encoded into .wmv format... which you'll need something like TMPG to bust up if you wish to encode it in something else.
I do not use Premiere at home, as I do not have quite the processing resources as I do at my job, so I tend to use something a little lighter but with around the same capabilities. Currently I'm using a program called Ulead MediaStudio, which I'm growing quite fond of. It doesnt have everything im used to, but its quick and effective, and it can take a bit more abuse than Premiere without throwing a temper tantrum.
It all comes down to time vs quality. For something quick, sure I'll swallow my pride and use Windows Movie Maker (actually sometimes it comes in handy, as it can be quite resiliant when working with unknown audio codecs, as most encoding utilities will barf at you), but if I have time to spare I'll crack something out with MediaStudio.