Highly Recommended: Bullzip PDF printer

Many programs let you export to PDF, but many others don't. For this, you need a PDF printer, which lets you print to PDF just as if you were printing to a physical printer. For this, my favorite program is currently the free Bullzip PDF printer. Get it at bullzip.com - no advertising or crapware is included. It works with all recent Windows versions including 64-bit. Donations are accepted. It's fast, simple, and works well.