THERE, in all of their Fourth of July glory, are 101 grilling ideas begging to be tried. A vast majority take less time to prepare and grill than it takes to watch your coals turn white. (If you use gas, they're still almost as fast as heating up the grill.) Some of them feature ingredients like corn, eggplant and tomatoes, which will be better a month from now, at least in the Northeast. But there are also suggestions for foods in season right now that not everybody thinks of putting on the grill. Please note that salt and pepper are (usually) understood.