I have been a scrapbooker since I got pregnant with my son almost 30 years ago. So ... when I started quilting it just seemed natural to keep one for that. I have pictures of almost all the quilts I have made since 1998 (when I started). Like you, I have pertinent information - size, batting, pattern name, book it came from, type of batting, who quilted, how much it cost to quilt, who it went to - usually a full quilt picture and some close-ups. It is great fun to go back and look at all the pretty quilts I have made.
I did the same with quilt shows that I went to - those got big very fast because of all the pictures. When I take those, I always take a picture of the label on the quilt, a full view and any close-ups. Now, I just keep those on my computer - sorted by each show, by year. I usually delete all the informational pictures once I have generated a word document with the information in it. I label all the pictures according to the quilt name given by the maker (2012 07 26 - Twister Quilt (1), 2012 07 26 - Twister Quilt (2) and so on).
I have discovered that I don't have all the pictures of quilts I have made on my computer - I can only assume those must be in my negative boxes - I really need to purchase a decent negative/slide scanner and get those onto my computer - it probably would be a good idea to do the same with the kids pictures too - lol