Getting lots of new folks here lately, thought this might be useful.
Feel free to add-on to this thread, remembering what you needed to learn as a noobie.
1) All P60-style light hosts (bodys) have the same beam. Really. You can take the drop-in (lightbulb) out of a $10 P60 light, and drop it in a $100 P60 light and guess what? Same beam. The body is just a host and a switch, so pay what you want, its the drop-in that is important.
2) When you see the words "Strobe" or "blinky-modes" or "S.O.S". it is usually not a positive thing to flashaholics. A few people like them, but they are of very limited real-life use and are primarily a marketing ploy to non-flashaholics. They are annoying because a 5-mode light makes you push the clicky 3 times just to go from Low to High, which should just take one click.
3) A FORWARD clicky will give you light with a "soft press" before the light actually clicks on, and the beam stays on as long as you keep soft pressure on the switch. You select the mode you want with soft presses, then 'click' on to stay in that mode. A REVERSE clicky makes you 'click' the light on first, then soft-presses cycle through the modes. Once you soft-press to the mode you like, taking your finger off the switch keeps the light on in that mode.
4) Before you try to figure out what flashlight to buy, you really need to know what kind of batteries you prefer. Knowing that will make buying a flashlight a much more enjoyable endeavor, so it is best to research batteries before you research flashlight bodies.
5) Once you figure out what kind of batteries you like, you need to figure out WHY and WHERE you will be shining your flashlight. Do you just need to light up a room? Your front yard? Your neighbor's front yard? The whole block? This determines how bright and how much "throw" you need.
6) And when you figure out what you want to light up, you need to figure out how long, how often and just how you plan to carry the light. Slip it into your pocket? Carry a holster? Use a strap to carry it over your shoulder? This will determine how BIG the light you need to buy should be.
7) Paying more money for an expensive flashlight does not generally mean you will get more light out of it. But more expensive lights may have warranties that lower-end budget lights do not have, and may be more reliable. That being said, people who buy expensive Surefires and Pelicans seem to complain more (on other web sites) about how many problems they have with their expensive torches. So spending more money is no guarantee that your light will be reliable or trouble-free.
8 ) There is no such thing as that one, perfect flashlight. If there was, I would gladly pay $500 for it and stop buying flashlights, but it does not exist.
9) SMO means smooth, OP means orange-peel, VLOP means Very Light Orange-Peel, they are types of reflectors, and affect whether your beam has a definitive, tight hotspot or more of a 'blend' from the hotspot to the corona to the spill.
10) As a corollary to #7 above, don't think for a second that just because you are in a Budget Light Forum, you are not going to spend a lot of money on flashlights. If you are reading this, you will drain a lot of money out of your bank account on xxx_fire lights that you never heard of before you came here. Sorry.