Dear Friend: What are the three main pointers to achieve realism in Poser 7? How can I make Poser images generally appealing? I have purchased many computer graphics software and tutorials without luck on the topic. Thank you. Sincerely, Fidelity2.

I can give you one main point. Lights.
I find it's the lights which will make or break the image, especially if you're after realism.
I no longer render in Poser 7 so there will be better qualified people than me on this. However, I would try using any HDRI or IBL sets you can.
Shaders are important also, the mega bagginsbill should be able to help you on this one.
Pose & expression. If the pose is realistic & the character has a proper expression & not staring blankly into space, this should be a good start.

If you mean real realism (like a photograph) done with Poser: Forget about it (at least an easy way simply isn't possible).

In my experience, the way to go to get "realism" is individual for each image, for each scene.
A girl with hair that looks like wax or rops won't look real. A face with teeth made out of wood can't look real. A teeny face with skin scaned from a 30 year old woman can't look real. Reflections without something like a skydome can't work (only few materials do not reflect at all - even skin-color is influenced by the colors around).
The list with such things is very long.

Oh, & don't forget postwork. Look at some of the best poser works in the gallery. You can be sure they've been postworked in some way. Whether it's for basic colour correction, filtering or after effects, it all helps to achieve realism.
My main point for postwork is to soften the edges on a figure & DOF. Look at a photograph, you'll generally find the edges around someone is slightly soft, subtle but effective. DOF is something I've come to like more for realism & it can vary from extreme to subtle. It's probably best to postwork this than to render it as it can take an age. Well, I know it does in Vue anyway.

Attached Link: Getting more realistic renders

In a nutshell:

#1 Lights and Shadows - you gotta tweak the crap outa these in Poser
#2+: shaders, pose, expression, environment

 It always helps to study the works of the masters. If you go through the galleries, pick the ones that look the best to you and try to tell what it is that makes them realistic. Is it a realistic expression? The way the shadows fall?

Then compare yours to that - do my surfaces show the same properties? If not, what do I need to change to get that effect? How do I make the shadows in my renders look the same? How do I get the same soft lighting?

Technical skill is nice, but it only takes you as far as your eyes see - just like drawing or painting, digital arts require you to see the things before you create them.

Is this pic attainable in just poser? I like this pic, but what models are used? and hair

That's Charlize 3.2, rendered with RealWorld 2.005. The hair comes with the model, but its shaders and morphs have been adjusted for the render :)

All kidding aside, it is possible to attain similar results with Poser alone, but it will take alot of practice to be able to do so. Buying realism kits and poses and this and that aren't always the best way to learn. The realism kits would be a good investment, but only if you are willing to actually go into the Material Room after applying one of them and study/tweak the settings.

Never use something "as if" :)
I mean, talking about the Realism kits, no kit would be perfect for every scene/lighting/effect you try to obtain. Everything has to be tweaked to match your lights and other.

Hmm, I think you meant to say "as-is".

Quote - Never use something "as if" :)
I mean, talking about the Realism kits, no kit would be perfect for every scene/lighting/effect you try to obtain. Everything has to be tweaked to match your lights and other.

I like the character in your avatar, I am still trying to get that certain look, like you did it, or similar to the one above as well, I use Vue, so if that is possible time for me to study vue more

Quote - > Quote - Never use something "as if" :)

I mean, talking about the Realism kits, no kit would be perfect for every scene/lighting/effect you try to obtain. Everything has to be tweaked to match your lights and other.

I like the character in your avatar, I am still trying to get that certain look, like you did it, or similar to the one above as well, I use Vue, so if that is possible time for me to study vue more

The character in my avatar is Stratus McCloud from Thorne at DAZ with the use of the Unimesh Realism Kit customed.When you say "the one above", if you're talking about Stormchaser's avatar, it's a photo ^^
And though i heavily render in Vue, this one is rendered in Poser.

Yep, my avatar is Charlize Theron, from Aeon Flux.