continualy squeeling brakes usually means the brakes aren't 'fine'. But if you have checked the pads and there is still some wear left in them then squeeling brakes can be caused by repeated "soft" braking applications, which gives the pad and disc time to glaze up or get shiny.
A good (and fun) way to temporarily fix this is by pulling up with near maximum breaking effort to roughen up both surfaces.
If they continue to squeel...then you will need to get the brakes checked out as the discs may need machining.