The book we're reading this month is Starfarers by Poul Anderson.
This one's available from Bookshare at
http://www.bookshare.org/browse/book/5988
(Listed as only in Good condition, however.)
It is also available as a digital download from the BARD site at
http://hdl.loc.gov/loc.nls/db.49154
Here's the NLS Synopsis:
Astronomers have discovered the possibility of advanced civilizations in the far
reaches of the galaxy. A group of ten scientists boards the starship Envoy for a
journey that will take thousands of years to complete. Although they eventually encounter
another civilization, they are unprepared for the ramifications of the adventure.
J. R. Westmoreland, Group Facilitator