It's nice to have, as it does act as a counterpart to the default generator for RTP assets. However, I wouldn't get the DS+ specifically for it... as a total package or add-on to the DS resources though it's great.
For tips, a few things that are easily ignored but so important particularly when you have few or no projects under your belt... start simple and be patient with yourself and your ideas. As with so many things, game creation is a skill that takes time and effort, and can be...
So I'm resuming work on the Shadowstar Trilogy. I've decided that it will take place between the end of G4 and the start of G5, and two of the Lost Rulers will be Twilight Sparkle and Sunset Shimmer (who is the moon princess in my AU).