I started with Pinnacle 4 or 5 when it came included with my JVC Camcorder way back when :)

I took up the upgrade offer and got the pro versions.

As far as simplicity and flow it is great for beginners, everything is layed out for you from start to finish.

But I wanted a bit more control so I bought Sony Vegas Pro, adding effects and text seems a bit clunky compared to Pinnacle.

Best advice, is to download the demo versions play with them and see what works for you.

I would also recommend Adobe premier but it is not for the faint of heart.