* Use a scanner - they are not very expensive
If you don't have a scanner...
* Turn off the flash - photograph in bright even light. Sunlight is good.
* Use the macro setting on your camera if you have one.
* Use postprocessing software to crop and adjust contrast and brightness - but don't do any other retouching 
* Make sure your camera is steady - a tripod that lets you rotate it to point down is bet (but at that poing a scanner would be cheaper) but just resting the camera against a solid object will help.
* I've found Fuji cameras have the best macro performance.
All know the way, but few follow it.