I have a weird question about covering something with glass….please help ASAP it's for Valentines Day?

So when my boyfriend graduated, his dad and went and put together a huge collage/picture board for him that had about 200+ pictures of him and his family ever since he was born. We stuck the pictures on a huge piece of wood (probably about 3.5’X4′). We just stuck them on with sticky tack because we thought we would just take it down after his party. Well he like it so much that he wanted to keep it and have it “framed” or put glass or some kind of protective thing over it. Well, we have never gotten around to it yet, and don’t really know how much it will cost, or what it all involves, or even where to look for something like that. I decided that I want to surprise him for Valentines Day and get it finished/covered. I’ve gone onto like Home Depots and Menards websites and it is no help. Can someone help me? How much will it cost? Any ideas on what it involves and what I have to do? Where I would go to get something like that bought or done? Any suggestions are open please….