I'm going to hire a guide in the next few days, for the first time in my life. I can remember hearing horror stories from my grandfather when I was a kid about guides who would show up drunk, or wouldn't show up at all.

How do I know that I'm hiring a reputable guide? Also, I understand that it is customary to leave a tip with the guide for a job well done. Is this tip expected, or is it really for a job well done? How much of a tip is acceptable?

thanks,
-Ray