This novel won both the Hugo award(1980) and the Nebula award(1979), in the "best novel" category. That's by no means a small accomplishment, heck, a lot of science fiction writers are happy just to get nominated.
The story deals with Vannevar Morgan, a highly accomplished engineer who want to take on a new, very ambitious engineering project. He wants to build a space elevator.
The idea of a space elevator is by no means pure fiction - it is theoretically possible. The idea is to literally build a cable that would be anchored on the surface of the Earth at one end, and a counter-weight at the other end, in orbit. This would make it possible to build elevator cars that could ride the cable into orbit. It would have an advantage over traditional rockets. You see, rockets have to expend a lot of energy and burn fuel just to maintain their position over the surface of the Earth when they're still close enough to feel the Earth's gravity strongly, and then use up even more energy to keep climbing. If you have a solid object sitting on the surface of the Earth that you can stand on or climb up, you don't have expend energy to maintain a position - so you can just focus your energy on increasing your altitude, and that is much more energy-efficient.
Of course, I'm not a physicist, but that's the way it's been explained to me by people who should know.
This novel shows Morgan go through several stages while trying to make the project come to fruition. First he has to try to get support and funding, which isn't easy. Many possibilities are considered, including starting on Mars instead of Earth; Mars has lower gravity, which would make the work easier. Of course, with two moons, one of which orbits quite closely, you might have a little problem if it ran into your elevator cable.
Throughout the novel, Clarke provides his trademark attention to scientific detail. If you like your science fiction to have good science in it - and I certainly do - you'll appreciate that. There are plenty of fascinating physics and engineering ideas here.
But it's not all just about discussing the science; the plot has some good twists, and some exciting parts. When the elevator is well on its way to completion, some problems make a daring rescue attempt necessary. Morgan has to ride up to a group of people stuck farther up the cable, and bring them life-saving supplies until they can be properly brought back home. These scenes show a nice interplay of the scientific ideas and some action and excitement.
Clarke is sometimes criticized for not having well-developed characters, although I'd say the lead character, Morgan, is a good character, and the supporting cast are written at least competently. But, of course, Morgan is the engineer whose story this really is focused on; it becomes a very personal story for him.
There are also some descriptions of the distant past and the even farther future, that show how humankind's ongoing aspiration to learn and reach beyond our limits can be truly amazing over time.
Anyway, I'd say that this novel is very good, and very consistent for Clarke - I wouldn't say there's any big departure in style here from his other works of read, which is fine - I like my science fiction with good science and bold ideas. An enjoyable read, well worth a look.