Yu-Gi-Oh Collecting and Dueling

What is the best way to organize Yu-Gi-Oh cards for both dueling and
collecting?

Is there a spreadsheet, database or full list online that we could use
to indicate which cards we have? I will probably put it into a
spreadsheet, but I should would like to do as little work as possible!

By the way, how many unique (American, English, Upper Deck) YGO cards
are there, now? 900? We have the Prima Card Catalog at 750+ and now
there is MFC.