Beginner... Model Scales and other fundamentals

I cracked open jME within about 2 weeks of now. Halfway through the tutorials, got to where it loaded models and applied textures. I also have been putting bits and pieces of my game together while I'm doing this to see how things are progressing. Our 3D artist has told me that 2 of the models are to scale to each other, but when loaded, i need to set different scale values so they look close enough as they should. What determines the size of an object when it is loaded compared to another that's supposed to be to scale?

I also figured out through trial and error how to load multiple models and textures and have them different. (possibly should be addressed within the tutorials to help save time? :smiley: )

Now for this second part, I'd like to follow some standards and while I could code any way that suits me, I'm big on doing things in a way that makes it easy for the person who picks up the slack after me. Is there already some tried and true methods to loading resources and the management of? Essentially I'm looking for any guidance that will save me from doing several rewrites later on.