I am creating a dark alley scene and would like to know how to light it.  My vision is to have the alley mostly dark and shadowy but i do need some accent lights set up. one of the lights i need is a wall mounted one with the light streaming down the wall and lighting a portion of the street beneath it. the classic bare light bulb spot light effect. how is this done in poser or do i have to export my models to another aplication and do it there. 
any advice would be helpful. 

Well if you want a light bulb effect, you ought to use a point light, which simulates a light bulb in that it emits light in all directions. You'll need to adjust the falloff settings, which would be Distant Start and Distant End in most versions of Poser.
Supposedly Poser 8 has better light falloff, but I don't t know what those settings are called or even if they work right.
For accents, you'd probably get better results with spot lights.

Step 2 would be after you get your lights set up, spend hours and hours and hours trying to get it all to look right...

Which leads directly to step 3, which you already alluded to: export everything to another 3D app... where you will quickly get far better results with far less aggravation.

It's not impossible to get good results with lights in Poser, and a lot of people do, and there are a lot of threads here about it. But it does take a lot of work and a lot of research and a lot of experimenting, so if you're not into that (like I'm not), exporting is a better idea, IMO.
Poser has too many limitations for large scenes requiring complex lighting, particularly outdoor scenes.

Maybe you like to read the following tutorials / articles in conjunction with your trials in poser.

Not directly Poser related but light in general:
http://www.itchy-animation.co.uk/light.htm
http://www.huevaluechroma.com/021.php

Poser related:
http://www.drgeep.com/NPU/Directories/dir02.htm
(on the lower left side of the graphic on that webpage you'll find the light tutorials)

When working with point or spot lights:
Search for ISF shader (inverse square falloff shader) made by Bagginsbill if you are not using Poser 8. You can attach that shader to the lights. By doing so the lights behave more in a natural way.

If you want an example of point lights using ISF, go to the link below.  Scene is lit by 2 point lights.

http://www.renderosity.com/mod/gallery/index.php?image_id=1941805

As for lighting your scene, I would:

• use a dark blue into IBL node to provide the overall mood

• without "nuking it", I would use a spotlight instead of a point light. I would make the falloff soft and set the color to light orange.

This wasn't rendered in Poser but you could reproduce something like this very easily.

 well if producing what i am looking for would be better( and more easily) achieved by exporting my models to another app....what app should i use?

Using examples from the itchy link, I sampled the light colors to simulate different environments within Poser using only directional lights. The top portion is a dark blue light that simulates "night-ness". The bottom portion is orange and simulates a tungsten lamp.

It should not be difficult to visualize how light color and attributes could be used to create environments similar to this in Poser. It's not the app, it's the theory.

Quote -
well if producing what i am looking for would be better( and more easily) achieved by exporting my models to another app....what app should i use?

Well, my vote would go to anything that has Mental Ray as a render engine... Maya, 3ds Max, Softimage...
If you have Poser Pro, it comes with hosting plugins for Maya, Max, Lightwave and Cinema 4D, which aren't very good in that all it exports is Poser stuff with simple Phong shading and textures, but at least the texture channels are already plugged in and you can expand on the surfacing from there.
But those are all high level apps and not really for beginners. In your first post you sounded like you had something in mind already.
All those programs have a fairly steep learning curve, especially the Mental Ray part of it, but they also all have fully functional 30 day demos to try out. I don't know about Cinema 4D though.
You could also look into Vue, as I think it comes in cheaper versions without all the bells and whistles, and Softimage has a completely free version called Mod Tool, which is made mostly for game modders and people who want to learn the program without the time limit of the demo.

Quote -
It's not the app, it's the theory.

I agree with that for the most part. Meaning, that works for most programs, but as someone who has spent a whole lot of time trying to get decent lighting out of Poser, I do think it IS the app. ;-)

I know that it's been said Poser 8 has improved on the whole lighting situation, but in Poser versions before that, for me it's been a seriously aggravating struggle to try to get Poser lights to do what I would expect them to do. Especially when you have multiple shadow-casting lights, which more often than not don't seem to play well together. And especially if you want "moody" scenes with lots of lighting subtlety. Poser's lights have very few options, mostly either On or Off.

Again, not to say it can't be done, but overall I think Poser is a pretty poor example of what can be done in 3D as far as lighting is concerned. It's stuck in the 90's.

Shadowrelm, the awesome thing is that you already know what your scene should look like. It's just a matter of executing it.

I didn't say it can't be done.
I did actually say it can be done.
Lighting something, even a few or many  things in Poser is a piece of cake.
I'm talking about complex scenes with complex lighting needs, which shadowrelm's first post sounded like it was going to be.
An outdoor moody alley scene would be challenging in any app, but Poser's limitations make it even moreso.

The wall texture, like the other one, is procedural. The wall geometry was exported from a modeler, everything else is straight Poser.

There is a low intensity IBL set to dark blue. There is a low intensity infinite light set to the same dark blue with its diffuse component dialed down. And of course there's an orange spot light, which has a 4X multiply node into light intensity in order to see it's affect on the wall. This unfortunately blows out the specular, which dialed way down.

I still like the first image better and it took far less time to tune.

 Looks good.

I'd say you're getting the hang of it. Good job so far.

Textures look good, but if you have higher res versions you might want to use those. It look like you have some pixellation and stretching.

Oh OK.
I see then that Poser 8 does have improved lighting. That would be a real pain in earlier versions, being that the light falloff was all wrong.

this isn't pure poser 8 tech. i took some of what the tuts you guys directed me to and incorporated that and came up with a solution.  I first created a sphere and surrounded it with spot lights. then parenting the lights to the sphere i was able to move them where i wanted the light to be.  then deleting either the top half or the bottom half of the "light sphere" and then deleting the sphere itself i was left with directional lights where i wanted them.  By selecting which lights to leave and which lights to delete i was able to pinpoint where the lights pointed at. the rest is a simple matter of light color and intensity. and by determining what kind of light it is (spot, point, direct) and so forth it allows me to change the mood.