Lammas Introduction (includes some history, God & Goddess):  "Welcome my sisters to this great day of celebration of the Lammas Sabbat.  This is the corn/wheat festival, honoring the first harvest.  We will honor it by partaking of corn and wheat, the earliest sustainers of life.  As the days become shorter, tree leaves will start turning color, mornings will become cooler.  The Goddess of Lammas..."
Lughnasadh originates from the Gaelic culture meaning festival of Lugh. It marks the beginning of the harvest season.  It was celebrated in Ireland, Scotland and the Isle of Man.  Lammas is a festival in England held on August 1st where the first harvest of corn or bread was blessed. It is also a Catholic festival. Below are a variety of articles we've added to our binder as resources.
http://www.druidry.org/druid-way/teaching-and-practice/druid-festivals/lughnasadh/deeper-lughnasadh
The link will take you to a website by Eilthireach from the order of Bard, Ovates, and Druids. It provides a basic introduction into the history of Lughnasadh.
Lammas History: Welcoming the Harvest- This article gives a little bit of information about: harvest, ancient cultures, a feast of bread, honoring Lugh, honoring the past, symbols and an idea for a ritual
Lammas (August 2) From The Women's Spirituality Book: A nice opening for connecting to history and the themes of Lammas.  It includes a lovely poem.
Lammas (August Eve): An article from the Women's Spirituality Book-This pdf (non editable copy) includes the Antiphonal Chant: "What is this night?..." 
Lammas (pdf):  This article is missing the first page, however there are four more pages with a wealth of information, ritual ideas and poems/readings to use. It was copied (long ago) from a book without a reference to its author.  
The Holidays-Lammas: Festival of the New Bread (Celtic): (pdf) "Lammas (Old English "Loaf Mass") is a festival of regeneration dedicated to the inventors of agriculture...the festival is connected with the movement of the soul between the worlds..."  More good information.
August 2-Lammas Celebration (pdf)  for editable version click here (From www.coolwomen.ca) :  This is a nice 1 page article (with some great images). 
Celebrating Lammas-(www.school of the seasons.com):  
Lammas History from the 1996 Ritual: (Brief but accurate)