Thoughts : You need to download a program known as CFGEdit, available here on Simviation. Great program, though it's buggy if you pick a copyrighted gauge. Then put the panel image in your aircraft's Panel folder, go into CFGEdit, do New Panel.cfg, find the image, select it, and start droppin in gauges. Save often, even though it makes a backup each time, you can delete those later, and it's better safe than sorry.

Good luck! NEVER NEVER NEVER NEVER NEVER give up! CFGEdit is gonna make you want to throw your computer across the room! DON'T! Go into F$, fly around a bit, burn some steam off, then go back and finish the panel. I just finished a couple of my own. I will post some pictures of the finished ones if you would like, they show the accuracy CFGEdit can do. 8)
Edit:
If it is really tickin you off, send it to me and I'll make a few changes to it, then send you back a background bitmap, showing all the gauges, but with no gauges actually on it, allowing you to put the gauges on it to get used to good ole' CFGEdit.

Here I said I would post what CFGEdit can do. I did all this in CFGEdit, none of it the manual way. I know some of the gauges are off but that is my own fault, I was in a hurry to make this so I could post it in another topic.