Comedy fantasy series with a Pratchetteque/Carry On Blackadder twist, but written for children. A slightly more sophisticated read than the Lost Diaries, with a bit more edge.

The Dark Forest is a world. Cities, towns and villages exist like islands in a green sea, while in the Forest itself live hermits, wizards and all manner of weird and wonderful creatures - some invented, some strangely familiar.

BOOK 2: WHIZZARD!
The story of Tym, apprentice to the local wizard, who accidentally invents a new potion that causes them to move at incredible speeds. (Not to mention some rather dire side effects!)