Realistically, you cannot follow a video guide or individual list for your "collectibles" run through this game. There's just too many things to watch for. You'll need to follow a sequential guide, and it will most likely ruin the experience, but these radios are not all on the beaten path.
Tyger7 has a great walkthrough available in a zipped doc here: http://www.xbox360achievements.org/forum/showthread.php?t=23...
I recommend using Dropbox or email to send this doc to your iPad/mobile device, so you can play in the dark!
As for the radios, there are ELEVEN you will need for this achievement. You can listen to these shows from the home screen and check your stats from the start menu.
Episode 1: A Famous Deerfest Guest, Have You Seen This Dog
Episode 2: Deerfest Floats Are Very Exciting, Doc Nelson’s Deerfest Plans
Episode 3: Synder’s Feeling the Pressure, Peabody Heard Gunfire, Lorna Miles, Humanitarian, Main’s Anger, A Conversation About Love
Episode 4: A Missing Persons Alert, Mulligan and Thornton Bicker
The three recordings in Hartman's office from Chapter 4 will also appear under Chapter 4, and there will be other radio transmissions to listen to, but these listed are the only ones that count. They are enumerated in the guide.