I read a portion of this book in the mid 2000s. It was a young adult fantasy story about an apprentice of some sort of magical guild that looked after the eggs of some species of animal (perhaps dragon?). These eggs were the power source that the magicians drew from. I feel like there was a parallel story going on in the real (modern day) world, but have no recollection of that side of the story.
I remember some imagery of a large egg (about 3 metres tall) that was partially underground as the cover art, perhaps with the apprentice and a stereotypical magician in a robe and hat.
At some point, there is some sort of awakening, that the apprentice senses when they wake up, which will help them graduate into being a wizard. I think his egg may have hatched?
I never finished the book, but it has been tickling my mind recently. It would have probably been in the 200-400 page range.
Unfortunately my recollection can be tainted by various other mediums, like His Dark Materials (parallel worlds) and Morrowind (kwama egg farms).