Free Yard Sale

This is a sizable project that will require lots of time, planning, materials, and volunteers. That being said, this is a great opportunity to open the doors of the church, show your community true hospitality, and offer simple items that can help out local families in tremendous ways.
STEPS

Set a date for the event allowing enough time for promotion, collection, enlisting volunteers and advertising.
Promotion (internal): Get the church excited about reaching people in the community through a free yard sale. Creatively promote your needs of donations and volunteers. Make flyers, promote it in the bulletin and church newsletter, but also consider making a video clip or posting a promotion on the church website. See a great example promotion video here.
Collection: Find a location large enough where items can be stored without being in the way.
Decide what items you want to collect and share the needs with the church (use bulletin boards, the church bulletin and newsletter, or email reminders). Suggested Item Categories:

Clothes (women's, men's and children's)	Furniture
Kitchen Items (appliances, accessories, and dishes)	Children's Toys
Sports Equipment (balls, hoops, bats, gloves, etc.)	Books & Movies

As items are collected, have volunteers regularly cleaning, sorting, preparing and categorizing the items. This will make the Big Day a lot more manageable.
Enlist volunteers to cover set up, the yard sale and clean up. Put up sign-ups and ensure all the tasks are assigned prior to the Big Day. Provide volunteers with easily-identifiable t-shirts if possible. Suggested Tasks:

SET UP	YARD SALE	CLEAN UP
Sort items	Direct traffic	Pick up trash
Set up tables & racks	Provide child entertainment (face painting, bean-bag toss, etc.)	Tear down tables & racks
Set out items	Serve refreshments	Gather signs
Place signs promoting free yard sale	Assist transporting larger items to car or home of recipient	Gather left-over items
Hang signs for restrooms and item categories	Monitor items and help people	Take items to local thrift store

Advertising (external) in the local neighborhood can be done using flyers, newspaper adds or door to door visits. Think about the best ways to reach your primary audience (low-income families or possibly refugees from other countries). Be sure to promote the free yard sale in Spanish or other languages when necessary. Make sure the community knows the items are free.
The Big Day should be lots of fun and energy, but expect challenges too. Don't forget to have a team praying prior to the event, during the event and after the event. Encourage volunteers to share the love of Christ both in word and deed as they interact with the community.

Tips

The best way to pull off such a big event such as a free yard sale is to enlist a team. Divide the three main responsibilities between individuals or groups. The responsibilities include promotion/advertising (internal/external), collection, and event coordinating (including enlisting volunteers).
If your church is too small to hold a reasonable size free yard sale then partner with another church or invite members of the community to contribute to the event.
Consider putting a limit on the number of items per category per family.
Consider recruiting bilingual volunteers.