Brake help!!

[Livin_AZ_Style!!]

I own a 1998 se Pathy. First off, three weeks ago, there would be this hissing/hushing sound whenever i'd push the brakes down and then let go. The only way the sound would disappear is if i push down enough on the brakes to stop it. I checked my fluids and nothing was leaking. Well, that was for the last three weeks.. NOW. As I drive and use my brakes, i hear this scraping sound from my driver front brake. Idk what exactly it is but i need help with both problems. Idk if there is a air or hydraulic system that prevents my gears from slipping into other gears but i need to know what's going on.. please help, ASAP!! any advice as to looking general locations would be nice or anything.