In the current edition of InDesign , how do I convert my indesign document into a PDF?

@John Waller's link to instructions is excellent, but it's a bit outdated. They leave out which type of PDF you need to make:

Traditional (press, print, etc.) or Interactive (for forms, multi-media, and accessible PDFs).

So when you do File / Export, you'll need to select either PDF Print or PDF Interactive. The rest of the instructions are valid for the PDF Print route.