I don't think you really need to bring anything at all. The only thing I personally ever bring when I'm babysitting is my cell phone, and maybe a sweatshirt. I'm sure the kids have plenty of toys and things to play with at their house... buuut if there's something at your house that you think the kids would really enjoy, then go ahead and bring it. If not, then don't worry about bringing anything at all. Do you have any cool craft materials at your house that you could bring? That could be fun. If you're babysitting a girl, you could bring nail polish. (Just make sure to ask the mom if it's okay first haha).
For yourself? or to do with the kids? for yourself, book, magazine, of course phone. So you can still pay attention or if they go for naps... To do with them coloring, movies.
Snacks for yourself, iPod, phone, comfy sweats, games you and the kids could do together, your favorite Disney movie.
book,phone,games, i would suggest an iPod because if the kids are calling you ; you might not hear them
Watch the baby ? watch a kids movie like Disney or whatever just make sure you watch them :P.
You would or wouldn't suggest and Ipod?
Duct tape and Nyquil...just kidding!!