One of our must-haves for any household. It is the story of who lives here. It's something to study while you are passing down the halls, standing in an entry, or waiting in a home office. The artifacts, photographs, certificates, fine art or prints of the inhabitants speak volumes! It's proof of a life well lived. It gives a home conviction. It tells your story. It layers the room with history. I'll be so bold to say, it makes a house a home!
When considering how and where to put your gallery, here are a few things to consider: If the contents are personal, you may want to avoid the entry, so you are not sharing those deeply personal pieces with just everyone. Save those for the more intimate gathering spots. You will be asked about the framed documents and photos by almost everyone who sees them so make sure you are comfortable with sharing those thoughts and memories.
You may opt to do a gallery of art in the entry. Less personal, but no less impressing.
The bigger the documents the better (especially if its a large wall). I'd try not to use anything smaller than an 8x10, even then, I'd use matting to enlarge the area.
I like it if there is something in common in the gallery. It may just be that you've used similar matting, all wood tones frames, or all black and white photography... The eye likes some form of commonality. Other than that... Go for it!
Tell your story!