Pseudocode for constant time modular exponentiation I'm looking to implement modular exponentiation (for RSA) in constant time, but most of the examples I've found are more mathematical descriptions of the operations. Are there any references with descriptions in psuedo-code, which are understandable (and implementable!) by someone without much of a math background?
No.  If you don't have a strong math background, implementing RSA yourself is a  bad idea (and perhaps even if you do).  There are many ways to go wrong, which can open up subtle security weaknesses.

Instead, you should use a well-vetted RSA implementation from a standard crypto library, and a well-vetted protocol -- or hire a cryptographer who does understand the mathematics, if you don't think you can trust any existing implementation or need help selecting one that is suitable.