Looking for an easy but scientifically reliable programme for making books, articles and documents accessible

In 1988/89 I made an inventory of my books (2000) with a Windows 2 programme. It could only digest 1000. So I had to separate it into 2 sets.
Later on, in 1994/5 I developed with Paradox a more sophisticated approach. Search on author, title, epoch, year, country, language, subject etc became possible. Citations could be inserted in articles and references simplified. I am still very proud of my development skills, but the 4000 books and documents I have to record at this point of time cannot find their place in my primitive Paradox records.
That is why I am looking for advice. I tried programmes designed for videoshops. No way.
I assume that libraries all over the world have good programmes to make their books etc. accessible. Are they 'on the market'?
Please, tell me about predesigned programmes for categorizing books and documents.
You will help me so much!