Do you have Microsoft Access? if you already have the scanned image files, all you need to do is set up a table with image names (some scheme may need to be developed), fields (columns of data) for searching (dates, subject, etc),, another field for the image path, and then a form or two -- one for searching and maybe another to display the image. You can start or build the tables in Excel and then import them into Access. There is a learning curve for Access, but there are plenty of cheap, used books on how to use it and lots on the internet, especially for the weird, tougher problems.
If you don't need to view the images on the screen right away, Excel is a good choice. As Dave says above, you can make Excel work for viewing. Besides the scanning, filling in the table with data is the most time-consuming part, whether you use Excel only or go to Access. You can also build the table using Access (controls on the form write to the table.)
The key differences is that Access has an Image Control, which allows a selected image to be viewed on a screen at any size you want, up to the size of your monitor of course, and has much better/easier searching capability than Excel. At least that is my experience.
I am hardly a software engineer, but I do have a science background, (PhD 1996), and my computer skills go back to punch cards and IBM mainframes, yet I seem to manage getting things done somehow.
If you really want to try this, I could probably help you via PM's or email. These days I have a little extra time.