I've found PDF printer drivers to be quite handy to share documentation since PDFs
are so much smaller and better suited for email. Also the other party doesn't need
any software other than free Acrobat Reader to print them out.
I like CutePDF http://www.cutepdf.com/ better than some other programs I
was trying before. Since most the time drawing set is collection of DWG files,
printing them on CutePDF produces number of PDF files (each page separate).
To merge them, there is another free utility called PDFTK http://www.accesspdf.com/pdftk/
it's just one EXE file that should be extracted somewhere PATH variable points to
(like windows directory), then create text file with following content:
PDFTK *.PDF CAT OUTPUT ALL_DWGs.PDF
You can name it MERGE_PDF.BAT for example.
Place this file in directory with all individual PDF pages and execute it (double click on it will do).
In a second or maybe two new file called ALL_DWGs.PDF will appear in the same folder.