What helped me a lot was a chart that came with a multi-sample library I bought. It shows the frequency ranges of many common instruments. I used that info when writing tunes to help with 2 things:
To avoid crowding frequency ranges with instruments that share the same primary frequencies.
To make sure I cover as much of the spectrum as I can.
I can't direct you to a chart, but I'm sure you can come up with something via google search. Even if you have to get the info for each instrument separately, it's worth it. Better arrangements, make for better and easier mixes since you won't have rely as much on EQing to make things fit.
Also, there are 2 post floating around in this forum where I answered similar questions with info I got from a mixing book. The info was more about mixing, but I apply it to arrangements as well.
This is one. Same info in the other, but I think I expounded a bit more. Try searching for my name and "arrangements" or "5 elements". It may be a few months old at this point.