Our guild has an annual Treasure Sale; one area is straight donation items to the guild for sale to members (all profits go to the guild), and the rest is comprised of tables rented by members to sell their quilting/needlework related items whether handmade, repurposed, gently used or never used (all profits go to the member seller, who can donate if they wish back to the guild). Items are new or gently used. Our guild is a 501(c)(3). Our IRS advisors told us that if we sell to the membership only no sales tax is required to be collected.
We also participate in several local seasonal events (spring, fall and winter) selling raffle tickets (with the required permit), handcrafted items and never/gently used quilting or needlework items. Since the venue is public, and sales are open to the general public, sales tax is required to be collected and paid to the state.
Some states allow participants in "flea market" and "garage sale" events to forego the collection and payment of sales tax up to a certain amount per year (for example, up to $5,000). It's a low amount on purpose since it's assumed that a garage sale is not a significant source of household income. I may have worded this poorly, but hopefully have communicated the rationale behind the exception.
Hope this helps - if you have specific questions, please post them with "NEED CPA ADVICE FOR GUILD" in the subject line - someone on the chat board's gotta be married to one!