I'd say the really good ones are dogeared with greasy fingerprints and spend their life jammed into the back of a shelf on a service van rolling down the highway.
beyond that, aside from some real baisc material, the book on boiler troubleshooting won't be much use for furnaces and neither will have much to say about electronic ignitions (a whole other set of info).
let me take a stab at it... the click click click thingy is doing it's thing but the whoosh hasn't kicked in (try cleaning everything) or it does whoosh ok but the fan doesn't start blowing and then it all stops?
(been a long day)