Remember, you get what you pay for and this also includes information. There is a few books in print that discuss this in great detail. A great low cost book is Glenn Newick's book "The Ultimate in Rifle Accuracy." A couple of other great books are Mike Ratigan's "Extreme Rifle Accuracy," and Tony Boyer's Book "The Book of Rifle Accuracy." Out of the three, I feel Mike Ratigan's book has the most complete information on bench set up. If you do want to glean information off of the internet, I would pick a trust source such as Thomas "Speedy" Gonzales time to time articles and post.
Such as http://bulletin.accurateshooter.com/tag/speedy-gonzalez/
and https://www.facebook.com/note.php?note_id=139212865272
and http://bentongunclub.org/smf/index.php?topic=806.0
The subject of proper bench set up, contains many chapters. There is several ways to skin the cat, and many different opinions on how to do it. According to the books mentioned most people get it wrong when they set up. Remember what I said, you get what you pay for? There is also a ton of products out there, some of it is good and some of it is bad, some of it works for some and some of it don't. With that said it takes a bit of experimenting to figure out what does. Just remember, the fanciest stuff is not always the best, but sometimes the simple stuff works better.
Here is a few tips I can give out. First the set up has to be solid, it can not move. Second, the set up must track good. When I talk about tracking, it means that you can move the rifle back and forth in the bags and it goes straight up and down and returns to the same aiming spot, if it don't then something is wrong. On bags, the front bags must not be hard, and the rear bag must not rock or shift. Last, the set up has to be comfortable, if your not, it just will not work. This relates to the placement of the rest and bag's on the bench, seat height, and body position.
In closing I have found that most of the best shooters use simple set up. Many use low end Hart or Sinclair rest with no windage top and a low end Protektor bag, and they are bag squeezers. They don't drag a bunch of stuff out to the bench. Some shooters will switch techniques depending on the conditions they are shooting in. There is three main techniques that most shooters use: Free recoil, Pinning the rifle in the rest, and look last.
