How do people learn to fix Apple products?

I'm really interested in flipping phones or iPods on Craigslist or eBay, but my question is (and I searched for the answer but couldn't find something to completely answer it), how do people learn to fix these handsets?

I could go online and find one for sale that says "Broken iPhone 4; screen cracked and won't turn on". The screen replacement is one thing, but how do people know what's making it unable to power on?

I guess my biggest question is where can I get more information on learning this stuff, and how the hardware in these devices work so I can start making a little extra money repairing them and reselling them.

Youtube video tutorial or find some one local whom can teach u

Call XpressFix, they will probably hire you! JK, if you want to learn you can look at their Apple repair videos or call for advice. They have sold me parts and are really friendly. They fix broken and shattered Apple iPads, iPhones, Macbooks, and iMacs.http://www.xpressfix.com or http://www.1hourcellphonerepair.com

  • Why do some people love to hate on Apple products? Especially guys. I know lots of guys who say Apple is overpriced and not that good. I have a macbook that is almost 4 years old and still works like it's brand new. Before I had to buy new laptops every 2 years because they became slow and these laptops cost the same as my mac. Also, I have the iPad and the Galaxy tablet and the iPad is way better. I'm even switching back to the iphone because the galaxy 4 is annoying.
  • Why do people like apple products such as iphones and macbooks? IN terms of phones Androids are BY FAR the superior device and also why would you spend over $1000 dollars on a macbook pro when you can get a toshiba touchscreen laptop with 1000 gigabytes worth of storage for only $699? Seriously i would like to know.
  • Why do people like apple products so much? I got a samsung galaxy 3 and my friends said I should have got the iphone 5. My phone is clearly better but everyone keeps saying apple products are better. What kind of idiots camp out infront of a store everytime a new apple product is released? I don't see what's so great about them.
  • How does people afford Apple products? So when I go downtown or the mall, I see many MANY people with iPhones, MacBooks, and/or iPads. Most of these people are young, as in their early 20s! I'm jealous because I wish I had a MacBook but I didn't know it wa possible for those to buy apple products because they're highly expensive. How do people pull through?