*look in the little free newspapers that come out during the week
to see what's going on for the weekend. I check on Thursdays and Fridays.
Do I need to get cash?
I would definitely take cash. A lot of people won't accept checks. I usually get a five, 4 ones, and 4 quarters and see how far I can make $10 stretch. This makes me really think about what I buy. If there is something for more than that and I really want it, I see if they will take a local check or hold it for me for a half an hour while I run get more. If you're on the hunt for big ticket items like furniture, of course you want to bring more.
Either. It can be a ton of fun going with other people, but if I'm on limited time I like going by myself because I know what I'm looking for and can move quickly from one to the next. That being said, some of my favorite yard sale memories have been with friends and family~being lost, trying to contain our excitement when we find a treasure, or wondering how we're going to fit that bookself in our little car, or where we're going to hide our stuff from our husbands. :) It's always nice to have a driver and a navigator as well.