See, the stuff that he got right is the stuff you've never heard of ;) And the reason you don't hear about it is because it's...well....boring. It's hard to describe all of the things that Pliny talked about, since he basically wrote an encyclopedia worth of stuff, but he covers things like geography...

At the narrow neck of the Isthmus, Hellas begins, by our people known as Græcia. The first state that presents itself is Attica, anciently called Acte. It touches the Isthmus in that part of it which is called Megaris, from the colony of Megara, lying on the opposite side to Pagæ.

These two towns are situate at the spot where the Peloponnesus projects to the greatest distance; being placed, one on each side, upon the very shoulders of Hellas as it were. The Pagæans, as well as the people of Ægosthena, belong to the jurisdiction of Megara. On the coast there is the port of Schœnos, the towns of Sidus and Cremmyon, the Scironian Rocks, six miles in length, Geranea, Megara, and Eleusis. Œnoë and Probalinthos also formerly existed here; the ports of Piræus and Phalerum are distant from the Isthmus fifty-five miles, being united to Athens, which lies in the interior, by a wall five miles in length. Athens is a free city, and needs not a word more from us in its commendation; of fame it enjoys even more than enough. In Attica there are the Fountains of Cephisia, Larine, Callirrhoë Enneacrunos, and the mountains of Brilessus, Ægialeus, Icarius, Hymettus, Lycabettus, and the place where Ilissus stood. At the distance of forty-five miles from the Piræus is the Promontory of Sunium. There is also the Promontory of Thoricos; Potamos, Steria, and Brauron, once towns, the borough of Rhamus, the place where Marathon stood, the Thriasian plain, the town of Melite, and Oropus upon the confines of Bœotia.

or birds...

Caius Marius, in his second consulship, assigned the eagle exclusively to the Roman legions. Before that period it had only held the first rank, there being four others as well, the wolf, the minotaur, the horse, and the wild boar, each of which preceded a single division. Some few years before his time it had begun to be the custom to carry the eagle only into battle, the other standards being left behind in camp; Marius, however, abolished the rest of them entirely. Since then, it has been remarked that hardly ever has a Roman legion encamped for the winter, without a pair of eagles making their appearance at the spot.

The first and second species of eagle, not only prey upon the whole of the smaller quadrupeds, but will attack deer even. Rolling in the dust, the eagle covers its body all over with it, and then perching on the antlers of the animal, shakes the dust into its eyes, while at the same time it beats it on the head with its wings, until the creature at last precipitates itself down the rocks. Nor, indeed, is this one enemy sufficient for it; it has still more terrible combats with the serpent, and the issue is much more doubtful, although the battle is fought in the air. The serpent seeks the eggs of the eagle with a mischievous avidity; while the eagle, in return, carries it off whenever it happens to see it; upon these occasions, the serpent coils itself about the wings of the bird in multiplied folds, until at last they fall to the earth together.

or about grafting fruit trees and making jam...

This branch of civilized life has long since been brought to the very highest pitch of perfection, for man has left nothing untried here. Hence it is that we find Virgil speaking of grafting the nut-tree on the arbutus, the apple on the plane, and the cherry on the elm. Indeed, there is nothing further in this department that can possibly be devised, and it is a long time since any new variety of fruit has been discovered. Religious scruples, too, will not allow of indiscriminate grafting; thus, for instance, it is not permitted to graft upon the thorn, for it is not easy, by any mode of expiation, to avoid the disastrous effects of lightning; and we are told that as many as are the kinds of trees that have been engrafted on the thorn, so many are the thunderbolts that will be hurled against that spot in a single flash.

The form of the pear is turbinated; the later kinds remain on the parent tree till winter, when they ripen with the frost; such, for instance, as the Greek variety, the ampullaceum, and the laureum; the same, too, with apples of the Amerinian and the Scandian kinds. Apples and pears are prepared for keeping just like grapes, and in as many different ways; but, with the exception of plums, they are the only fruit that are stored in casks. Apples and pears have certain vinous properties, and like wine these drinks are forbidden to invalids by the physicians. These fruits are sometimes boiled up with wine and water, and, so make a preserve that is eaten with bread; a preparation which is never made of any other fruit, with the exception of the quinces, known as the "cotoneum" and the "strutheum."

or about stone and carving...

In making their statues, these artists used the marble of Thasos also, one of the Cyclades, and of Lesbos, this last being rather more livid than the other. The poet Menander, in fact, who was a very careful enquirer into all matters of luxury, is the first who has spoken, and that but rarely, of variegated marbles, and, indeed, of the employment of marble in general. Columns of this material were at first employed in temples, not on grounds of superior elegance, (for that was not thought of, as yet), but because no material could be found of a more substantial nature. It was under these circumstances, that the Temple of the Olympian Jupiter was commenced at Athens, the columns of which were brought by Sylla to Rome, for the buildings in the Capitol.

Still, however, there had been a distinction drawn between ordinary stone and marble, in the days of Homer even. The poet speaks in one passage of a person being struck down with a huge mass of marble; but that is all; and when he describes the abodes of royalty adorned with every elegance, besides brass, gold, electrum, and silver, he only mentions ivory. Variegated marbles, in my opinion, were first discovered in the quarries of Chios, when the inhabitants were building the walls of their city; a circumstance which gave rise to a facetious repartee on the part of M. Cicero. It being the practice with them to show these walls to everybody, as something magnificent; "I should admire them much more," said he, "if you had built them of the stone used at Tibur." And, by Hercules! the art of painting never would have been held in such esteem, or, indeed, in any esteem at all, if variegated marbles had been held in admiration.

I'm terrifically sorry for the quotespam here, but I literally just randomly flipped through some books of Pliny and gave you four passages at random from among them - the point being, it's far easier (and generally more entertaining) to point out the things that Pliny gets wrong, rather than right. He's sometimes our only source for some things (like prices of spices), and he's generally held to be relatively reliable, despite his muddling of some topics. If you'd like to browse some more about his works, check out this link, which gives you a full translation, as well as the original Latin. The translation isn't exactly amazing, since it was written in the 1850s, but it'll give you a good idea of what Pliny discusses, and you'll be able to get the idea of the concepts that he discusses, whichever ones raise your fancy!

If you've got any more questions, feel free to ask - Pliny's a fun one, and I, personally, find the Naturalis Historia to be fascinating.