It depends highly on the type of restaurant you're working in. It any decent restaurant, you can probably expect a minimum of $30-40 for a 5-6 hour shift with a decent chance for close to $100 or more.

I worked in restaurants for years. Be aware that it does require a certain amount of people skills and patience and you will be on your feet for long periods of time, but it can also be very rewarding.

If you have any questions, feel free to PM me. I'm not an expert, but I've worked in close to 100 restaurants that ranged from Pizza Hut and Village in to Red Lobster and several country clubs.