From the File menu, choose Export. Choose PDF and the type of PDF you desire to create on that dialog box.
PDFX-1a and PDFX-4 are safe bets for your job. If your job has elements that bleed off the page, make sure you look at the section for printers marks, and that crop marks is set, along with any other options your printer specifies (like page info, color bars, etc).
Take care, Mike
Important: Don't use the brochure functionality in InDesign, don't print to a pdf, export it as PDF.
Ask your printer how he needs his PDF. Ask for his requirement as Output Color Space, bleed, register marks, PDF standard, etc. Then export this PDF as single pages from your InDesign. Let the printer do all imposing things.
Never create a PDF via printing, only via Export. Even if the printer suggest to do so.