How do you get lighting to work with sky? I dont want to have to add a thousand lights and the world spawn lighting is not working.

You have to use skies with "_light" after their name. For example, if you use the "yavin" or "bespin" sky, you WILL require light entities around your map unless you set an ambient light value in your worldspawn but it will make your map look unrealistic since ALL areas will be lit in the same manner!
If for example you use a sky like "artus_light", it will light up your environments realistically, and indoors, you can use light entities like in real life

My tutorial covers it. View my tutorial on "Skyboxes" at JK2 Mapping:

http://www.geocities.com/jk2mapping

You might be interested in other tutorials too!?

Kayron James Mercieca - JK2 Mapping

But your Tutorial just says use a light entity... isnt there a better way it would take so many entitys to light it and even then it would be bumpy and unreal.

Add a line to your sky shader like such:

q3map_sun <red> <green> <blue> <intensity> <degrees> <elevation>

For a normal white light, juse use 255 for red/green/blue. A natural bright sun intensity is 100. Degrees tells you which side the light is coming from (ie 90 = north, 180 = east, 270 = south, etc). And elevation is like what time of day it is (ie 90 = noon, straight up). Hope that helps.

-JK

My tutorial explains how to do stuff without the modification of shaders...
Which might be more limited, but it does the job!
I have made a map with a sky with no "_light" and I have managed to realistically light up my map with light entities, indoors and outdoors...

Kayron James Mercieca - JK2 Mapping

On the same topic..... I have my shader made, and all the textures painted. So my shader is basically this:

textures/hoth/hothsky
{
qer_editorimage textures/hoth/sky.tga
surfaceparm noimpact
surfaceparm nolightmap
surfaceparm sky
q3map_sun 1 1 1 70 244 15
q3map_surfacelight 80

skyparms env/hoth/hothsky 512 -

}

called shaders/hothsky.shader. The textures - sky.tga, and hothsky_rt.jpg, hothsky_lf.jpg etc. - are in textures/hoth.
Now, It doesn't work. I don't have the game atm cos I've lent it to a friend - do I need to change the shader name to hoth? or alternatively put the textures in a different folder called hothsky?
Or is it something else. This is the stuff I've worked out, coupled with some information like above for adding suns to it. Atm it basically has the colour of sky.tga and emmits light as it should. Please help.