Children's / YA book involving demon summoning and a sorcerer's apprentice

Question

I'm trying to identify a book. The things that I'm certain of are:

• The main character is male and a sorcerer's apprentice or something. Probably a child / young adult.
• There's demon summoning, involving circles.
• It's a (dark?) children's book (maybe late primary school age).
• I read it around 2005, in Australia.
• It's not The Bartimaeus Trilogy.

Things I'm not so sure of:

• I think main character's name starts with 'R.'
• I think the copy I had was about the same size and thickness of a Deltora Quest paperback.
• There may have been one or two pictures inside.
• The cover might have had red on it.
• There might have been something involving a doppelganger (much less certain about this).

Thank you. :)

Answer 1

This might be School of Wizardy, first book in Debra Doyle's Circle of Magic books. Randal leaves his training as a page to apprentice as a wizard. He has the usual trials of a protagonist at a wizarding school with snooty students who've paid tuition while he's basically there on scholarship, difficulty with his magic (it's established that he has great power, but correspondingly worse control), and people distrusting him for his background training as a warrior (one of the rules for Wizards is that they cannot wield weapons without losing their power). The climax of the story does involve a summoning circle with a demon. I don't remember a doppelganger, though.