Many tombstones are hard to read due to age and weathering
Take chalk to help outline the hard to read letters
Take care to assure you transcribe everything on a tombstone exactly as possible
be sure to describe anything unusual on a tombstone
If possible, try to wait until the sun is at the best angle for reading and photographing a tombstone
Take the picture at a 20 to 30 degree angle to make use of shadows on the letters
If you can read the tombstone in a digital camera's screen then no need to handwrite the info too
Many libraries have papers done by some wonderful soul who spent the time transcribing all tombstones for one or more cemeteries, then placed a copy of the labor of love in the local library