The required textbook for the course is the 8th or 9th edition of Physical Chemistry by
Atkins and de Paula.
The course web page has been updated soon to include the Syllabus, Calendar, and the first homework assignment (due Wednesday, August 29).
Note that the two Math Review assignments can be found on the Homework page.
Active Thermochemical Tables - This has the most accurate values of enthalpy data (frequently updated). Unfortunately, this database is somewhat limited in scope.
NIST Chemistry WebBook - Lots of valuable data on thermochemistry, spectroscopy, mass spectometry, etc. See links to other NIST databases
JPL Data Evaluation #18 - Section 6 has enthalpy and entropy data for many gases of atmospheric interest. Section 3 and Section 5 has a few equilibrium constants and a number of Henry's Law Constants (!! but read the Introductions to these sections for notes on units !!).