On Schedule M, you’ll report non-cash contributions you’ve received. You’re required to submit Schedule M if you reported at least $25,000 of non-cash contributions on Form 990, Part VIII, line 1g, or if you received contributions of art, historical treasures, or similar assets, or qualified conservation contributions, even if you didn’t report revenue for them in Part VIII.
Part 1 lists 24 types of contributions you may have received, and has 4 unlabeled lines for any contributions that don’t fall into the categories listed. If you received multiple contributions in the same category, lump them all together on that line. Don’t include donated services, or donated use of facilities, equipment, or materials, either on Schedule M or elsewhere on your Form 990. These contributions will be a reconciling item on Schedule D, Part XI.
Check the box in column (a) for any line where you received a contribution in that category. In column (b), report either the number of gifts you received, or the number of items you received, and note in Part II which method you’re reporting, or a combination of both. For gifts of securities, report each gift as an item, rather than each share you received.
In column (c), report the amount of revenue you reported on Form 990, Part VIII, line 1g. If you didn’t report revenue, list 0 here. When you’re done, the total listed in column (c) should match the amount you report on Part VIII, line 1g.
Report the valuation method you used in column (d). Examples of valuation methods are the cost or selling price of the donated item, the sale of comparable items, the replacement cost, or the opinion or valuation of experts. For Part VIII and Schedule M, use the same valuation method that you use in your financial records.
Answer the questions on lines 29-33. On line 29, Form 8283 is something donors have to fill out for non-cash contributions which they’re claiming a tax deduction for. The donor would ask you to sign it, acknowledging receipt of the gift. You can find the form and instructions here and here.
Line 31 asks about gift acceptance policies for non-standard gifts. For this purpose, non-standard refers to contributions of items which you don’t reasonably expect to use to further your exempt purpose, and for which (a) there’s not a ready market where you can sell the contribution and convert it to cash, and (b) the value of the gift is highly speculative or difficult to ascertain. In general, it’s good to have a gift acceptance policy, even for standard gifts, and you can read more about such policies here.
Schedule M can be found here. More detailed instructions for filling it out are on pages 3-5 of the linked document.