To explain where we are coming from, what if I told you I wanted to set up a reef tank. I don't care to learn about how a protein skimmer works or why I need one, why metal halides differ from a T5 setup because my turtle died and I'm just going to use his old basking lamp, why power heads are beneficial because the hang on the back filter from the turtle tank will move plenty of water, and don't even get me started on a sump. I don't want to have to learn anything about plumbing. All I want to know is the very basics.
While this sounds like a perfectly reasonable request to someone who hasn't done any research yet, most people on RC would roll their eyes and say research, research, research because you are way over simplifying things! DSLR photography (aka Xsi photography) is no different. You are going to have to get some research under your belt if you want to take pictures like everyone else who convinced you to buy it in the first place.