If the brake fluid has never been replaced it has quite likely absorbed enough moisture to cause corrosion of the caliper pistons; this causes them to stick in the bores and they will not retract once the brake pressure is released. This corrosion will be on the inside of the piston bore, and will damage the seals and cause fluid to weep around the pistons. However sometimes the part of the piston which sits outside the caliper bore will get gooped up with road grime and weeping fluid and stop the piston from retracting.
If the corrosion gets bad enough you will need to replace the calipers. A scrub out with steel wool and new seals will not solve the problem. However, for a short term fix, remove the calipers, take out the pads, and remove the rubber boot around the piston. Spray the exposed portion of the piston liberally with brake cleaner and try to push the piston all the way back in the bore with a 'G' clamp. Replace the pads and have someone gently push the brake pedal down, while you ensure that the piston does not come out too far (having the pads in place should prevent this). Work the pistons in and out a few times. Replace the rubber boot after cleaning off excess brake cleaner and cleaning up the piston as much as possible.
Having the brakes stuck partially on will lead to premature wear of your brake rotors and pads, and increase fuel consumption. You will notice that the wheels are extremely hot after a run.
BTW if your brake lines are 'cracked', you should see plenty of weeping fluid, which attracts road grime; also pretty soon you won't have any brakes at all!