Lughnasadh (the three most common pronunciations are; loo-NAS-suh, LOO-nah-sod, or loo-NESS-uh) takes place on August 1st in the northern hemisphere and February 1st in the southern hemisphere.  This is my explanation of this holiday.  It may or may not work for you and your path.  There are a number of things that this Sabbat usually celebrates: 

•  Fertility (in plants, animals, and humans)
• The first harvest
• Honor the God Lugh
• Honor any other deities related to the harvest (there are many)

Some ways of celebrating culturally are:

•  Creating a feast with harvest foods
• Baking bread
• Making jelly or jam
• Making tomato sauce
• Preserving food (canning, jarring, etc.)
• Going on a picnic
• Going for a hike
• Singing
• Playing games, especially outdoor games
• Plan a BBQ with seasonal foods
• Make crafts using corn and corn husks

Some ritual ideas are:

• Imbibe food with intention or energy and eat it
• Make sacrifices to the local land wights, fae, or whatever else you believe in
• Gratitude for things that have come to fruition
• Fire magic
• Fertility