What are cash outlays & expected inflows for an individual miner? I'm a student and a beginner interested in learning about Bitcoin. I am not interested in attempting to mine at this time, but I would like to know more about how it works. 

Per my understanding, adding to the blockchain requires brute-force computing. I know some amateurs attempt to mine with relatively simple setups, spending maybe a few thousand dollars to get the necessary equipment. I also know that others spend significantly more to create complex setups that, all else equal, I would assume are much more effective. 

Generally speaking, what are some estimates for what people might spend to get set up to mine bitcoins? Given what people might spend, what might they expect to earn in a year if constantly mining? What I'm most interested in knowing, for context, is what type of an "investment yield" does the average miner generate? For example, if I spent $5 on equipment and earned $25 in a year, my return would be 20%. 

Thanks for your thoughts!
There are a bunch of mining profitability calculators here. You just need to fill in how much you're going to spend on the equipment, what sort of hash rate you get from the equipment, how much you pay for electricity and what you think bitcoin will be worth and it'll tell you. These are all highly dependent on what you buy, how much of it you buy, where in the world you are and what bitcoin price will be. Investment yields will differ based on those factors.

An ASIC machine manufactured 2 years ago in Paris is going to be much less profitable (or basically lose lots of money) vs. getting a bulk discount on the latest ASICs in Iceland.

Also, this is a question that gets asked quite often.