OH, one more thing: Don't take in new stuff unless it's top shelf. Avoid projects.
Tax write-off won't help most people... very few people can actually take advantage of it, as the default deduction for that area of the form is usually higher than any donations made over the year. If it were me, I'd do a yard sale and price all the cheap stuff at a few bucks. I'd make some money back and clear some space at the same time. Then, I'd do CL for the nice gear.
When you reached your limit will just listening to the music be enough?
As far as I know, anyone who itemizes can deduct charitable donations. I'm sure there's limits, but we have been taking these deductions for years. Church offerings, charity donations, GW donations, etc.
Good luck on the cleanup, I'm doing one at my house too!