I'm using Paint.net for editing logos, works perfect for me, and it's free. I'm also using clear logos as my main display, and I'm creating them all the time for games that don't have clear logos in the database. I recently did around 500 of them for my C64 collection, which I posted in the forum here.
You could also send some pictures, or tell what you want, and I could help you out. No wizard either here, but I was also learning by doing, once you try and learn 4-5 tricks which make your life easier, it's quite straight forward.
One thing is for sure, if you're using an existing picture to start with, it has to be good quality, because creating a logo out of a 200x120 pixel picture ain't gonna work.