I know there are a bunch of these sites and programs, and I have tried a few, but I found a great web site to PDF converter called " web2PDFconvert". It is extremely easy to use and very quick.
I read a lot of tech and pc articles, many of which I like to save for future reference. So, I like to save them in PDF format. You can just open this site, which is FREE for private use, enter the URL of the page you want to save and it converts it to a PDF in several seconds. You can then save it to your hard drive or external drive.
I also installed their tool button in Firefox, so when I have a website open where there's an article I want to save, I just click the web to PDF button on the browser and it automatically converts that page I'm on into a PDF. You can also elect to have a PDF emailed to you, but I've never done that. I just find this one to be very easy and very quick.