When I first tried my hand at designing - I got a trial version of Photo Impact and then when the 30 day trial ended - I wanted to try something else (for comparison) so I tried a 30 day trial of Photoshop Elements 5.0. There were cool things about each program but I personally liked the Photoshop Elements 5.0 better - so I went ahead and purchased that one and have been using it ever since.
My advice to you is to get online and find the free trial versions and try your hand at them. You will find it may take quite some time to learn what all the buttons do - so be prepared to stick with one program for the 30 days before deciding. If I had decided after only a week or so, I probably would have given up. Just be patient and be willing to try and experiment with all the buttons/features. And if you want to try more than one - don't do them at the same time - I think it may make it harder on you.
I hope this helped!