Coin Graders Credentials?

I went to a local coin shop on Friday and asked if he would grade the coins. He said no as he would be interested in buying some of my quality pre-40s coins and made me some offers which I did not accept as I told him he was my first stop. He said if I wanted them graded I should send them to a 3rd party grading service. He rattle off a few but I did not write them down.

Any suggestions here and idea of cost of this service? Is it cost effective to do this to sell them for coins under $100. in suspected value? Should I just grade them myself with the use of the Red Book and cut MY thoughts on their value by one grade since I am a novice?
I am trying to be cost effective to sell these coins but still want to be fair to buyers and not misrepresent them.

Also I have been looking at some coins for sale to see how others are marketing theirs and I am seeing some other grading sources with initials I don't recognize. Is the Red Book grading typically recognized by all coin collectors?

Not all dealers are going to be as unhelpful as yours was; it depends on how busy they are, and on how regular a customer of theirs you are. If you've spent lots of money buying coins at a coin dealer, they're usually happy to spend time chatting with you next time you visit. If, however, they get the impression you're mainly interested in selling and likely to become one of their competitors, they're probably going to be a lot less keen about training you up.

Sending coins away to a third party grader does cost money. Usually, this additional cost can be recouped by sellers because people tend to pay more for coins in TPG slabs, especially if the sale is on ebay or other online venues.

Sending coins to be graded is, of course, a gamble; it's entirely possible you pay them your money and send the coins off to be graded, only to have them sent back to you ungraded because the TPG believes the coins were cleaned, damaged, fake or otherwise ungradeable. Or the coins come back with much lower grades than you were hoping for.

If you wish for personal, face-to-face assistance with learning to grade coins yourself and your local dealers aren't proving very helpful, might I suggest visiting a local coin club. As the members there are your fellow collectors, they also are neutral "third parties", and unlike most dealers they usually have lots of spare time for newbies with questions and are happy to help out a novice learn more about the hobby, for free. The can also help you spot the most obvious examples you might have of cleaned, damaged, fake or otherwise ungradeable coins.

My advice would be to wait for a local coin show. Then hit 5 of the bigger dealers and sell to the highest, and/or get their input. If you want to keep the coins, then you can study coins at the show, and begin the long (never ending) process of learning to grade coins.