There are three main tiers for eating: the stalls, the food courts and restaurants in the fancy malls, and the fancy restaurants and buffets in the fancy hotels.
Oddly, standard stand-alone “restaurants” play less of a role here than in any other major city I know. (Stand-alone stores are also less important, could it be that the hot weather and traffic encourages a clumping of retail visits into large malls?) And the very small restaurants can be good, but overall I think they are dominated by the stalls.
When it comes to the stalls, you will stumble upon a bunch and then you can simply choose what looks good. Stalls in the better parts of town appear more salubrious and indeed probably are.
The food courts are good, and clean, but too homogenized for my taste. Plastic trays reign.
The fancy buffets I would never go to if I lived here, but they are a good way to sample many dishes during the course of a meal. I recommend them for tourists and newcomers. The key to eating well from them is to choose those dishes which require outside aid for their assembly.
The key question is then the optimal ratio of stalls to fancy buffets, and that depends on how many days you have in town. The fancy buffets are also better for some of the fancier dishes, for instance as might involve lamb or crabs, or for dishes from other regions of the country.
And that is how you eat well in Jakarta. Knowledge of specific restaurants is not the key here.