Our local Feline Rescue Society does what they call a "FurBall" - they raised about $25K this year (each year is has increased). What they do is to sell tickets for $20 per ticket and everything is auctioned.
Individuals, businesses and organizations donate the items to be auctioned off (both silent auctions and a live auction). They use a local TV or Radio personality to actually perform the live auction component. Items range from a dog watcher, pet sitter, dog/cat items, antique furniture, dinners, a year of vet services, food, weekend getaway's, gourmet dinner prepared at your home, in home pet photography (which is an item I actually bid on and where my picture w/my cat in the yearbook came from

In addition to the auction items, local restaurants, caterers, etc. are all asked if they would like to donate food & desserts - it's not anything fancy but they do a buffet before the live auction starts - and it's when everyone walks around and bids on the silent auction items.
It's alot of work going into it - you need volunteers to perform all kinds of tasks, but it's a sell out every year and keeps getting bigger and bigger.
In addition to the Furball, they also hold an annual StrutForStrays and the target this year is $25K for that.
The biggest thing - get sponsors, don't have the group pay for anything - there are individuals and organizations out there that will cover the cost of everything.....name the item and you'll find someone to pay for it!!