I do quite a lot of this. On Windows PCs the easiest way is to use a graphics word processor (e.g Word) to create your document then a free program called "PDF creator" which you install as a printer driver. You just print the document to this and it comes out as a PDF. It's at
https://sourceforge.net/project/showfiles.php?group_id=57796 The complete Windows version with installer is about a 14mb download.
The only snag with the versions I've used to date is that the PDFs it creates won't load properly into the Mac "preview" PDF viewer; you have to install Adobe Acrobat to read them. But Acrobat is free anyway so that isn't a problem.
There are equivalent programs for Mac, Linux, etc. - Macs save documents as PDFs anyway, but they come out as huge files so this isn't usually the best answer.
One thing to be careful of - If you create a PDF containing graphics it will store the full sized graphics files, even if you squash them small on the page. You can end up with teeny images that are still very slow to load. The best answer is to resample them to the right size in a paint program before putting them into the document.
Another problem that can happen is that fonts don't reproduce properly - the answer here is to embed the fonts into the PDF, which any PDF creator program should be able to do.
Here's a link to an RPG I publish that was created this way - there's a sample file of a few pages that's free to download, not very exciting in terms of layout etc. but I think it shows just how simple this stuff can be:
http://e23.sjgames.com/item.html?id=ROW001 This was finished off using Adobe Acrobat Professional, incidentally, so will load into Mac preview without Actobat installed. But Acrobat Pro is hugely expensive.
Hope that this helps.
