Mounting glass pictures

Hi

I am new to this and would like to mount a series of 3 small (coaster size) glass pictures on white wood/board. I don't want a frame, just something really simple. I don't know exactly what I am looking for nor how best to glue them to the board/wood, should I find some. Be very grateful for any advice as I have spent ages looking at websites for mountboard etc but am not sure if that is what I need! Many thanks!