Thinking more about it, I think that making all the bibliomancer's potential evocations as rotes that he accesses by reading from a book really works. Here's why.
Let's say I'm a budding bibliomancer with 4 discipline, 3 conviction. I'm headed into a nasty situation, so I make sure to have my copy of Grave Peril at hand, knowing that it's a good book for summoning up some punishing firepower.
The fight starts and some nasties are swarming over my friends in the next zone. Thinking quickly, I page over to one of my bookmarks, a scene where Harry unloads a few rounds into a vamp. The GM decides that it's a weapon 2 attack (a normal gunshot), requiring 2 shifts of power to cast and that's it. I'd like to put some more force into that hit since I could easily control it, but bibliomancer's can't be choosers and I don't have time to find another page. I agree, and cast the spell.
In the next exchange I get charged by one of the enemies, and I'm having a tough time getting through their armor. Fortunately I know that they are vulnerable to faith type magic, so I flip again in my book to a scene where Susan throws holy water into a hot spotlight, creating a deadly blast of holy steam. The GM rules that it's a weapon 4 attack that cuts through the enemies' toughness power: great! Just enough that I can get the most out of my control while still casting it, and by carefully choosing the appropriate passage I got a little extra oomph out of the spell for free.
Later in the fight we aren't doing so well, and I flip to the page where Dresden lets loose with fuego pyrofuego. The GM looks at it, calls it a weapon 6 attack with an extra 2 shifts to target the whole zone: I need 8 discipline to get it off. Hope I saved some fate points, I'm going to need them.