Lighting can create a mood or simply make sure you can see your framed photographs at their best.
 
Unfortunately once a photo is framed behind glass it becomes prone to reflections.
 
You could use Non-reflective glass but there is a tradeoff, this glass softens the image and slightly mutes the colors, sometimes this is the only solution when correct lighting is not possible.
 
Still the best way to remove reflections is proper lighting then can you see all the color and detail of your photograph.
 
The best lighting is tungsten, it is warm and pleasing.
You can use adjustable ceiling down lights or lights on rails.
These lights should point down at approx. 45 degrees to the photo.
 

How many lights do you need.
For each 20" photo - one light.
For each 30" or 40" photo - two lights.
For each 50", 60" & 70" photo - three lights.

Use these numbers for the best lighting.

Creating mood lighting.
Light the photograph and not the surrounding area, the light will lead your eyes to the photo.
 
This effect can look fantastic at the end of halls, in the middle of a wall or in darker rooms, in fact anywhere you want to create a dominant feature.