Doors and Windows - Doors won't close, uneven frames?

A number of doors in my house won't close. The doors seem to have sagged and I have to lift them to get the lock to go into the strike plate hole. I've tried shims with little luck. They seem to move me closer to being able to close the doors without actually straightening them. I step back to look at how the door lines up and I can tell that it's off. Do I have to take everything apart and reframe or adjust the current one? I'm not a do-it-yourselfer at all but I'm determined to be. Thanks for your help.

John

First make sure the hinges are tight to the jam and door. Running a 3 or 3 1/2" Deck screw through the second hole in the top hinge might press the jam back enough to enable the door to shut properly. You could also enlarge the latch hole with a file or remove it, chissel the hole to enlong it and reattach the plate. Use an awl to make new screw holes if they will be close to the old ones. Finally, you could pull the door, casing and set the jam however I would try the above if the door top is still sitting above the jam stop.