OK

I've put a skybox around my map and deleted some of the walls now. The sky looks great, but in reality the map doesn't just end at the sides and then there is sky.

1) What I am after knowing is how is it possible to put those perspective textures on brushes where it looks as though your in a garden but the houses carry on and on into the distance....? Or another example would be a chicken wire fence is the map boundary but when you look through it the floor stops and you can only see sky - but in reality you should be able to see everything that lights up the horizon. Sorry if I haven't explained this well.

2) Also, my map has become brighter since I put a skybox around it but it's still not bright enough really. Will I need to go and add separate light entites where it needs a boost or can i add a 'SUN' entity in someway?

Thanks for any help.