What light bulb is recommended for reading for someone with macular degeneration?

Stronger. Some compensation for the diminshed vision of macular degeneration is possible by increasing the light intensity. Solar corrective bulbs can also help; with this. These improve the vision a little but will not affect the course of the macular changes.
Bright white light. People with macular diseases in general are "light starved" so directed bright white light is best. This can be from sunlight and 100 w incandescent bulbs. The brightest bulbs are probably halogen or led lights but they are more expensive.
Contrast is key... People with macular degeneration who have relatively good vision remaining oftentimes have problems with reading. This can arise from blurring and most importantly from loss of contrast. Halogen lamps work well since they are bright and improve contrast as well as some lens tints. Be sure optimize the angle of the light to minimize glare.