Pros
I worked at Sam's Club part time one summer as a membership associate. They payed better than all of the other stores in the area, and the work environment was pleasant for what it was. Their scheduling, as with most stores, sucks - they pick random hours and days for you to work. You can request off certain days pretty easily though, so its not so bad. I'd work there again if I was looking for a part time summer job. Also, once you've worked there for a bit, I believe you can move up to management positions fairly easily if you're interested. They offer training courses and stuff like that.
Cons
-Random hours / schedules (like most stores, I think) -pay is pretty bad compared to anything besides minimum wage jobs -you have to stand the entire time you're there (again, like all stores)