"Receiver" is another term you may run across. A "receiver" is an integrated amplifier along with a tuner (which is an AM/FM radio) in one box, i.e., a tuner, preamp, and power amp in one box.
For someone starting out, I wholeheartedly second going "all Nad" for electronics with one possible exception. If you will be buying a CD player and have as much as $500 to spend on that one component, then the player to get is the Oppo 103. For someone starting out, I also wholeheartedly second going "all bluejeans" for ALL cables.
As for speakers, I second two fundamental rules of thumb already mentioned: (1) devote approximately 50% of total budget to speakers, and (2) don't buy any speaker that you cannot hear first.
Over time as someone has more money and decides to get more into this "hobby," one finds that further investment often finds its way into power conditioning, power cords, cabling, room treatments, and various and asundry other tweaks. And no doubt, there may be worthwhile investments to be made in these areas. Just be aware, however, that these are also the areas where the most money is likely to be wasted because of the degree of trial and error and guesswork that's involved.
Last but not least, when researching specific products, never rely purely on a review in any print and/or online publication that relies primarily on advertising dollars for its lifeblood. Most of them rarely say anything negative, and when they do, they sugar coat the negative finding to such a degree that it no longer comes across as the negative that it is. I'm not saying don't read the Absolute Sounds of the world but just make sure to also read forums like this one and several others.