I work for nonprofit 501(c)(3) organization and I plan to donate a few items for this organization. Can I make this donation tax-deductible? Is it a problem that I work for them (and I will have their W2) on my tax return?
Valuation is a constant problem any time you donate non-cash assets to a charity... whether you work there or not.
The issue is obvious. You say the item was mint condition and want to claim its sticker price; IRS says it was a worn out piece of junk and wants to give you $1. Justifying valuation is all on the donor. The charity isn't even involved; their duty is to write you an acknowledgement letter saying that you did, indeed, donate certain items and state their condition not their value.
At audit time, you must prove value to the IRS, using any means which will persuade a tax court judge.
As an insider, you are totally allowed to donate. Of course, at audit time, any such donations will face increased scrutiny, as IRS may investigate whether the donations are phoney. Signing the acknowledgement letter yourself is probably a bad plan.
An audit could come at you from two directions. First an audit of your personal taxes obviously. Second an audit of the charity's Form 990 annual tax return. Being an insider increases the reporting threshold (makes it more likely) that your identity and your gifts would need to be disclosed on the 990... which is a public document, seen by many, any of whom could report a matter of concern to the IRS.
And one more thing. You are not allowed to deduct the value of your work product. Say they need a sign in front of the building. You put $100 of materials into a sign you normally charge $1000 for. You donate the sign. You can only deduct $100. Now, the auditor can see the sign on Google Street View and can affirm it exists, and looks like a $1000 sign. He won't look twice at $100 in matériel, its believable.
The risk is that the IRS doesn't believe you made the donation. So you counter this by having proof. Money by check or credit card is good.in fact this is a recent change to the tax law.
If it goods you are donating then get a receipt. Even if the amount wouldn't require it. Also have an appraisal so that you have a third party determining the value.