Get a buddy, have them sit in the drivers seat while you crawl under the car where the puddle is. Have said buddy push the brake pedal down and look for the leak, this might require some more brake fluid but its worth it...and its not real expensive. Find the leak, that'd be the best place to start. My guess is that a line blew, its no big deal, you'll just have to have it replaced. Its not hard to do yourself even if you dont have any experience with it. Just put it together the way you took it apart. The only difficulties you might have will be bending the lines. You dont have to get them bent the same as the original but if you can get it close its best. Just get it out of the way and not hanging down to catch on stuff...otherwise you're right back to where you started. The guys at the auto store should be able to help you with getting the right length of brake line. If you get too much, just coil the exess because its a bitch to cut. Not sure what it would cost if you took it to a shop, my guess is anywhere between 75-175 dollars...all depends on labor.