Ancient Calender
In order to make your research more fruitful and expedient, the library has provided two sources for each topic - a source of basic knowledge and source of advanced knowledge, that will give background not only of the calendar, but of the society itself.
Aztec
Basic knowledge
Calendar Zone -- Though apparently built by an amateur calendar enthusiast, this site has a good introduction to the topic.
Advanced knowledge
Encyclopedia Britannica
Babylonian
Basic knowledge
The British Museum's Babylon exhibit -- Though this is geared toward younger students, it is actually an excellent introduction to the topic.
Advanced knowledge
Encyclopedia Britannica
Chinese
Basic knowledge
Doggett, L.E. "Calendars" -- scroll down to Chinese calendar
Advanced knowledge
Encyclopedia Britannica
Egyptian
Basic knowledge
http://www.mnsu.edu/emuseum/prehistory/egypt/dailylife/calendar.html
Advanced knowledge
Encyclopedia Britannica
Hindu
Basic knowledge
The Brihaspati Project
Advanced knowledge
Encyclopedia Britannica
Islamic
Basic knowledge
Doggett, L.E. "Calendars" -- scroll down to Islamic calendar
Advanced knowledge
Encyclopedia Britannica
Jewish
Basic knowledge
Calendars and their history -- scroll down to Hebrew Calendar
Advanced knowledge
Encyclopedia Britannica
Julian
Basic knowledge
Doggett, L.E. "Calendars" -- scroll down to Julian calendar
Advanced knowledge
Encyclopedia Britannica
Mayan
Basic knowledge
http://www.astronomy.pomona.edu/archeo/yucatan/karenstrom.maya.html
http://scienceworld.wolfram.com/astronomy/MayanCalendar.html
http://barrickmuseum.unlv.edu/families/maya/calendar.html
Advanced knowledge
Encyclopedia Britannica