My kids used to go to a school that raised over $200,000 at its auctions. My biggest piece of advice is to never underestimate how much time this will take. Our auctions were every other year b/c it took two years to plan and get the items. The auction consisted of a couple hundred silent aution items in a half dozen or so categories and 65-70 live auction items. Some of the live items brought $10,000+. There also was a dinner and auction tickets were in the $100 range.
Don't try to do too many live items. It takes a lot of time and people totally lose interest after a while. We found that you needed to start with three or four things that were sure to sell but that wouldn't be that expensive. The really big items were between #20 and #50 after things were really rocking (and quite frankly, after people had had a few drinks). Make sure to mix up things, too -- don't do trips, sports memorabilia, etc. -- all in a row. Combine items into packages, even with the live stuff, to make them look more interesting.
If you're doing this for a school, I can tell you a way to make some big bucks if you have parents with $. At our school, each class made an item for the auction under the direction of the art teacher. For example, fourth graders did a chess set. A grandfather who was a skilled craftsman made an inlaid wood table and the kids painted the pieces. Went for over $10,000 the year my child was in fourth grade. Kindergarten made quilts -- handprint designes that were quilted by someone. One class did tile top tables and were helped out by that same grandpa. Some kid art was in the silent auction and only brought a few hundred dollars, but the chess set, quilts and tables were big items in live.
The biggest item at our auctions was always a wine tasting party. It was organized by a wine collector who was a former school parent. The package even included door-to-door transportation in a school bus! Usually went for about $30,000!
There was a place at our auction for people with a lot less $ like us. We always worked on auction night -- 50 or so parents were needed and it actually was a lot of fun. I produced the catalog, too, so I was involved all along. I usually spent about $100 on a silent auction bargain or two -- one year I got 60 pairs of tights!
Disney used to give four one-day tickets one time only -- they said don't ask again! For local businesses, you need to contact them directly and, if possible, have someone who actually does business there to do it.