Good idea. But it's not simple. Actually, very little of what we do is soundbyte simple.

There is a good diagram of those things at the geistware.com link I listed above. You can actually play with that application and get a feel for those things. And see how they change relative to each other. When a guy is designing his own model, he very often uses what geistware.com does so easily for you, but he uses it "backwards". He changes the spans or areas or whatever to see how that affects the stability. anyway......

I've got more than one BOOK that explains those relationships. The explanations work for almost everything that flies, from my parkflyer to the C5As that were being built over my head when I worked at Lockheed. Some things like flat foamys have some unique quirks, but for the most part the basics do apply if not perfectly. The basics..........

An airplane with a bigger wing than tail will have a neutral point that's more toward the bigger part. The smaller part is there to stabilize the bigger wing in pitch. For the tail to have a chance of doing that, the CG has to be ahead of the NP. How far ahead it is affects how much work the tail has to do to keep the wing stabilized. Not far enough, and the tail has no hope. Too far ahead and the tail winds up wasting all it's effort carrying the artificially imposed load caused by the CG pushing down on it's side of the NP. Move the CG from it's safe aft location toward the safe forward position and the elevator usually acts more and more sluggish and most people call that more stable. It's usually just an elevator that's being used up carrying a nose heavy CG around and having less deflection to cause pitch changes. etc etc

There are a number of really good model airplane books that tell all about this stuff. The LHSs in my area carry all of them usually. A couple are about trimming for flight. A couple are about designing models. Leaf through 'em and see if they might not be worth the time and money. You won't be learning flying field BS and wasting time.