I have to admit, I was sceptical at first. George RR Martin was not someone I had expected to find writing a fantasy novel, far less one which was billed as the first in a multi book cycle.

Don't get me wrong, GRRM is a fine author, but his previously published work has largely fallen into the Science Fiction genre and more often than not been short stories. Still, I was intrigued enough to buy 'A Game of Thrones' despite the publishers kiss of death "not since Lord of the Rings" style recommendation.
Fortunately I was not disappointed.

You'll forgive me I hope for not delving too deeply into the plot, but there are a fair few shocks and surprises in story for the lucky reader and I believe these books are best enjoyed without spoilers.

A Game of Thrones is the first in the sequence and introduces the main characters, geography and culture. The story is told in the 3rd person with chapters which focus on particular characters and the events surrounding them. This successfully provides different perspectives to the unfolding events, but we are rarely (if ever) taken through the same event twice.

The main protagonists of the first book are various members of the Stark and Lannister families (the great houses of nobility in the 'Seven Kingdoms').
The setting is pseudo-European medieval in terms of culture and technology, though there are also fantasy elements (viz the existence of Dragons and apparent use of Magic).

The plot centres around the intrigues, ambitions and loyalties which attend the Court of the King Robert Baratheon. The King is himself a usurper, the previous incumbent Aerys Targaryen having been murdered (though seemingly deservedly as he is painted as thoroughly depraved and corrupt). Needless to say this (among other factors) makes the regime unstable and inevitably it all goes horribly wrong.

The country is plunged into civil war and the leaders of the various factions declare themselves to be Kings in their own right. The events of the civil war are played out in the subsequent novels 'A Clash of Kings' and 'A Storm of Swords' in which the various protagonists hatch plots, make wars, get lost, kidnapped, killed and scattered across the land.

There are two other stories interleaved with the 'main one' and these center around Jon Snow (bastard son of Eddard Stark) and Danaerys Targaryen.
Through Jon Snows eyes we are introduced to the threat of an ancient evil from the North. A great wall of ice has been created (many years in the past) in order to keep this threat at bay and it is also useful effective against incursions by the northern barbarians and outlaws. But the various keeps and castles along the wall have fallen into disuse and disrepair over the years and the threat isn't taken as seriously as it used to be. Cue barbarian hordes, 'ice zombies' and evil 'fairie'.

Danaerys Targaryen is the main survivor of the previous dynasty and over the course of the three books sets about gathering her forces in order to reclaim the throne of the Seven Kingdoms.

In less skilled hands, the host of protagonists and multiple views of events could easily have become confused, but GRRM manages to combine the complex storytelling with strong, convincing character development with apparent ease.
Over the course of the three novels so far, what were (or seemed to be) central characters move off stage, sometimes permanently and further characters step into the limelight to carry the story forward. GRRM establishes fairly early on that his heroes are mortal and this helps give the story a freshness and feeling of reality.

A true ensemble piece and one in which the heroes and villains are equally interesting and all capable of acting well or badly depending on the circumstances and their motives.

Anyway, I've waxed lyrical long enough. Some people like a comparison with other authors to help them know if they'll like a book. The only series that comes to mind is Tad Williams "Memory, Sorrow and Thorn", but frankly this series main strength is that it is a bit different.

All you really need to know is that they are a great series of books, trust me, I've no reason to

Read them and enjoy.