While you can download OpenOffice free, the one thing that MS Works has that is virtually unique today is its flatfile database. If you want to create a database of just a few thousand records (say cataloguing a private collection) then a professional relational database management system is gross overkill. If you are not already familiar with programming RDMS then you are going to have a steep learning curve.
Years ago, there were plenty of flatfile databases to be had, but today MS Works is pretty well unique in general purpose databases. Because it does not build lots of index files and takes the data into RAM, it is easy to use and very fast. If you want to create a smallish database, look no further. MS Works is your best option.
The word processor and spreadsheet application may suit you if your needs do not extend beyond writing the odd letter and doing very simple calculations, but for anything beyond this I would recommend you download OpenOffice. It is the database that makes MS Works worth having.