What's Your Strategy For Grading From Pictures?

I find I go to this page and click on the type of coin I want to grade. Each has the same guidelines as listed in the Red Book for basic grading. http://www.coincommunity.com/us_coin_facts/
The rest comes from my experience but I still often have to look at those simple guidelines quite often.

The experience is a personal thing I think. Each collector earns their own education and pays the dues to get it.
I think we all learn from mistakes.
Ask the seller for better images politely if you are really considering the coin and explain what you want to see and know as far as those points go on luster and strike quality. If they really want to sell the coin and are good sellers they will try to accommodate you. If it is just a $1.00 coin, well I can see where they might not respond with a great effort but some still will answer you with a reply even if the sale does not involve a lot of money.
Sometimes you can only work with what you have in those lower quality images. Sometimes you eat the bear, sometimes the bear eats you. I have ended up with coins that were way better than expected, but I had a hunch they might be when I went with poor images.

You shouldn't be. Grading is a bit vague for most people. I know I stink at attepting to grade a coin. I go to many coin shows and usually amazed at how even dealers have some really poor grades on their coins. Some are what to me appears way under what I thought and many others are excessive. I've gone to many coin stores and see the same thing, lots of guessing. There are numerous books on that subject and as already noted even the Red Book has numerous explanations of grades.
I sometimes think coin dealers are like used car sales people. They'll tell you what they think you want to hear.

By all means, buy the books. But also, register at Heritage Auctions (ha.com) and take advantage of their huge archive (1.4 million coins and counting) of high-resolution images from past auctions. That will give you a feel for how the major TPG's grade coins; you're going to probably see some differences from "official" standards.

Grading from photos is a gradual process, experience built on experience. What you see in a photograph is not what you'd see with your eye. Keep in mind, a photograph large enough to grade from is far larger on your screen than the actual coin is, and minor marks will be magnified as a result. Generally speaking, the more accurate the photograph, the more likely you are to miss the actual grade on the low side. These are corrections you need to learn to make subconsciously.

Of course, there's also the completely unrelated skill of interpreting poor photographs. It's extremely difficult, and it really pays to be a photographer yourself so you'll have an understanding of what it took to make a shot look that bad. Improper white balance? Shot on an angle? Poor focus? Too wide an aperture, meaning insufficient depth of field?

Filling in those blanks can only be achieved with experience, and a lot of it. I cannot count the thousands upon thousands of images I've viewed - for instance, I look at every single 1921 Morgan offered on ebay, and as of this writing there are 3000 of them. I've also shot a few coins of my own; there are 8800 of my own images archived on this computer, I didn't transfer the whole archive to this new machine and that's only the ones I kept.

And I'll tell you plainly, after all this I'm only "getting" good at it. I still get burned on occasion by an ebay purchase I misinterpreted.

I'm not trying to discourage you - this is an absolutely necessary skill in the age of the Internet - but I wish you to have a realistic idea of what's involved.

SuperDave sort of said what I was trying to say only he explained it all. I just took the short version.
I've acquired a few books on grading but never got around to even opening them which is probably why I know so little about grading.

Coin Grading books are a start to learning the art but you will still need coins in hand to go along with the books. It takes many years of looking at thousands of coins to become somewhat comfortable without having to use a book reference. Also grading the photos on websites is a skill aquired after grading coins in hand, not the other way around. It's always best to learn grading without the use of magnification as the dings get magnified and appear larger than what they are. Also because Strike is very important photos can't really show this because they are not 3-D. Good luck!