Here's my list of the coolest dragon books. I'll list them from my least favourite to most favourite. :)

Dragonsdale series by Salamanda Drake 

1: Dragonsdale 

2: Riding the Storm

A nice series, mainly for girls, about living on an island where people ride dragons instead of horses and have dragon riding competitions. Age: 8+ 

A Gift of Dragons by Anne McCaffrey

This is a collection of 4 short stories, set in the world of Pern far in the future. One of the stories is rather boring and didn't feature dragons, but the I loved the others and they were great. The three stories that I like, Ever the Twain ,The Smallest Dragonboy, and The Girl Who Heard Dragons, are all about kids meeting their dragons for the first time, riding them, and bonding with them. Age: 10+ 

Dragonology Chronicles by Dugald A.Steer

1: The Dragon's Eye

2: The Dragon Diary

3: The Dragon's Apprentice 

4:The Dragon Prophecy

An exciting series for kids, set in the old days a long time ago, when two kids, Daniel and his sister Beatrice, spend the summer learning about dragons and go on action-packed adventures looking for them. Age: 10+ 

Jeremy Thatcher, Dragon Hatcher by Bruce Coville

Part of the popular Magic Shop series. A boy discovers a secret shop selling all sorts of magical items and buys a dragon egg, thinking it is a marble. He is very surprised when it hatches into a baby dragoness, and he has to be careful no-one sees her... Age: 8+ 

The Dragon of Lonely Island by Rebecca Rupp

A very good book that I enjoyed. Three children stay on a secret island in the holidays and discover a intelligent, talking,three-headed dragon in a cave who tells interesting stories, each head having a different personality and telling a different story. Age: 8+ 

Dragon Orb series by Mark Robson

1: Firestorm

2. Shadow

3:Longfang

4:Aurora 

Dragon Orb is an awesome series filled with suspense and action that makes it hard to stop reading! In the world of Areth, four young dragon riders, Nolita, Pell, Kira, and Elian, must retrieve four magical orbs in a dangerous quest to save the Oracle, with their day, night, dusk, and dawn dragons. Each different type has a special power: day dragons can breathe both hot, destructive fire, and healing fire that doesn't hurt; night dragons can turn invisible, dusk dragons can turn inaudible, and dawn dragons, being the most powerful of them all, can create portals to our world. Dusk is often my favourite time of day but my personality would probably be better for a day or even a dawn dragon. Having a day dragon would be awesome, because their fire heals injuries instantly! (Imagine how few people would ever go to hospital if we had lots of day dragons!) I highly recommend this series to people who want to become dragonriders.Age: 12+ for battle violence

Wings of Fire series by Tui T.Sutherland 

1: The Dragonet Prophecy

2: The Lost Heir

3: The Hidden Kingdom

4: The Dark Secret

5: The Brightest Night

6: Moon Rising

7: Winter Turning (not yet released)

Since Wattpad is packed with Wings of Fire fanfiction, you might already know about this popular series. Five young dragons,Sunny, Clay, Starflight, Glory, and Tsunami, are destined in a prophecy to stop the horrible war for a new SandWing (desert dragon) queen. Being imprisoned in an underground cave all their lives, they set out on a treacherous adventure to fulfil the prophecy. It is full of action and like the Harry Potter series, it is difficult to stop reading! Age: 12+ (because of battle violence, quite strong sometimes) 

Inheritance Cycle by Christopher Paolini

1: Eragon

2: Eldest

3: Brisingr

4: Inheritance 

I remember how popular this series was when Inheritance came out! A poor teenage boy, Eragon, finds a polished blue stone in the forest thinking he could trade it in for some money, until the egg hatches into a beautiful blue dragoness, Saphira! His life is transformed as Eragon becomes one of the last dragon riders in the land of Alagaesia. Age: 12+ 

Dragonkeeper series by Carole Wilkinson 

1: Dragonkeeper

2: Garden of the Purple Dragon

3: Dragon Moon

4: Blood Brothers

5: Shadow Sister (haven't read it yet) 

Along with the Merlin's Dragon trilogy (I'll mention that later) this series is the most emotional. Set at least a thousand years agp, a poor Chinese slave girl's life is changed forever when she meets Danzi, an old Chinese Dragon, and later, his son Kai. Ping becomes a dragonkeeper and goes through many hardships until she finds the dragons' home. Usually I would not cry at sad events in books or movies, but I cried when I read the end of one of the books (And that's saying something! Hope there aren't too many spoilers I've written down) Age 12+  

Dragon Kiss by E.D Baker 

Most of these books are action-packed with fierce battle scenes, but Dragon Kiss is an exception. If you want a more relaxed romantic comedy, than Dragon Kiss is for you. A young ice dragon, Audun, is in love with a human girl who can turn into a dragon, Millie. Before Audun can woo her and learn to transform into a human he must go on some exciting quests! I could relate to Millie, I'd love a dragon boyfriend and being able to turn into a dragon! :D Age: 10+

Shadow of the Dragon series by Kate O'Hearn

Part 1: Kira

Part 2: Elspeth  

I just finished this series today and it is brilliant! It's about two young sisters, Kira and Elspeth, who live in a kingdom ruled by a cruel king who has unfair rules against girls. When her home is burnt down by the evil Lord Dorcon and her sister Kahrin kidnapped, Kira and Elspeth go on a journey to fulfil the prophecy of a girl dragonrider defeating the king and riding a dragon called Jinx! This series has a lot about girl power and dragons! Age: 12+

Merlin's Dragon trilogy by T.A Barron

Of all these books, this series is near the best of the best! It's about a little lizard, Basil, living in the world of  Avalon, who so desperately wants to be big. His wish is fulfilled when he meets Merlin, a kind, powerful wizard, and goes a journey filled with action, humour, and fantasy. I love how the author respects nature and has his own inspirational quotes at the beginning of each chapter. Age: 12+ for battle violence 

Have you read any of these books? I'd like to know what you thought of them. :)