Both strategies have their place, depending on which set of readings you're studying at a given time.
When you're studying 音読み【おんよみ】(the Chinese-derived readings), it's best to learn the sound first, and then learn a couple of words that use it with each reading so that you can get a sense of when it's used.
To use your 人 example, learn that it's pronounced じん, then find words that use じん—things like 日本人【にほんじん】 and 人類【じんるい】. Then move on to the next reading (にん) and do the same: 人間【にんげん】、上人【じょうにん】, etc. The words don't have to be exotic; as a matter of fact, picking ones that you commonly use is ideal when possible.
The great thing about this strategy is that it enables you to make educated guesses at new words if you haven't seen them before, but know the character's meanings and probable readings. You won't always get it right on the first try, but the skill refines itself over time and practice.
One of the biggest mistakes I made with 訓読み【くんよみ】(native Japanese readings) was to start out learning many of them as just readings, devoid of distinct meaning. Let's take an example:
The character 見 has a collection of general meanings regarding vision ("look", "see", etc.). But if all you know about it is that it has to do with seeing and you have 3 possible verbs to use, how do you tell which one?
In cases like this, it's best to suck it up and put in a bit of extra effort to learn the actual meanings of the words associated with the readings. In this case:
- 見る【みる】: to see
- 見える【みえる】: to be seen; to appear
- 見せる【みせる】: to show
As you can see (forgive the pun), the general meaning of "see" isn't completely off the mark, but the choice of which verb to use depends on which dimension of that meaning you're trying to convey.
Another thing to be aware of is that sometimes some 訓読み are more commonly used in conjunction with something else, instead of as standalone words. Moving back to your 人 example, we have the following:
In this case, 人【ひと】 can stand on its own, meaning "person". The other two mean "person" as well, but in slightly different contexts:
- り is used as a counter for people when using Japanese numbers (ie. 一人【ひとり】、二人【ふたり】. These usually switch over to 人【にん】 appended to Chinese numbers starting with 3: 三人【さんにん】、十人【じゅうにん】, etc.)
- と is used in some words that combine two 訓読み readings to refer to "one who does something". For example, 狩人【かりうど】 combines the verb 狩る【かる】 ("to hunt") and と (slurred into ど) to create "hunter". It also appears at the end of some names (e.g. 隼人【はやと】).
Just because a reading is listed under a kanji doesn't necessarily mean you're going to find many examples of it out in the wild, especially as a foreigner. 生 famously has about 20 readings, but many of them (such as な・す、む・す、and お・う) really don't come up often, while others overlap with contextually more specific characters (活ける【いける】、産む【うむ】). Likewise, KANJIDIC (which is the source of most free online kanji dictionaries) has occasional errors or archaic/hard-to-find readings (e.g. it lists 二び【ふたたび】, which is a valid reading, but rather obscure).
In short, if you're having trouble finding examples of a reading in use, don't stress over it; move on to the next one on the list or ask a native speaker to help provide you with an example.