At the prison, Meyers said he would take sheriff's job and high-tailed it. I persuaded NCR to pardon him. Am directed to go back to tell Meyers he can have the job, but there is no pointer towards him and he isn't in the prison? Is this a glitch, or have I goofed up?
Thanks for any help.

^{Never mind. I found the svcker and completed that quest. Now, If I can only find Nash . . .}

Nash should be in his house (Mojave Express - look for the house with the huge sign "Mojave" on top), which also serves as his trading post and the Mojave Express station. It's also the place where you find ED-E.

Also, keep this link handy. It will answer a lot of your questions: http://fallout.wikia.com/wiki/Fallout_Wiki

If you've never spoken to Nash, he sits in the casino and just waits until you talk to him, then moves to his house.

Otherwise, yeah, he's hanging out in the Mojave Express office.