Don't touch it with a bargepole.
The main problem is that using it can change files you are NOT altering and corrupt them, so the only safety net you have is to make a complete back-up of your HoI2 DDA folder.
Your best bet is to use the editor to 'look' at stuff and get a feel for things, but don't edit anything.
Editing is best done manually by opening .csv files in Notepad (or another text editor) and having a look in there to get your bearings. You will soon figure it out (look at the HoI2 Wiki site for pointers).
Having such a 'hands-on' approach is really enjoyable and worthwhile. It also allows you set regular schedules as you back up a file alter it, and be able to know what is causing errors (which you can't do with the editor).
make small changes, load up the game to see if it works and so on. It means you have full control over the modding process.
Good luck.
Ayeshteni