Here's a great link that I found by way of Last In, First Out. It's from the Data Center Design blog. The article is Server Cabinet Organization tips.
It's full of great advice. Here's a sample:
4. Use perforated front and rear doors when using the room for air distribution
8. While they are convenient, do not use cable management arms that fold the cables on the back of the server as they impede outlet airflow of the server
Lots more, too. Some may not be pertinent to us, like #12:
12. Have a cabinet numbering convention and floor layout map
If I had a big enough datacenter to need a map, I'm hoping that I'd have been in the job long enough to naturally discover that, but nonetheless, it's a good list.
Here are a couple other links of interest I gleaned from LIFO: