cs_a42

This map's r_speeds is too high for playing it smoothly. The whole map is visible, see almost all the leaves see
http://img258.imageshack.us/img258/8347/csa420001to1.png
This cause lagg problems. Use SKIP-HINT, tut here:
http://twhl.co.za/tutorial.php?id=71
or rebulid your maps with more corridors. Read more about r_speeds and how to reduce it, here:
http://twhl.co.za/tutorial.php?id=38
There arent any furniture or stuff in it, which makes it a little bit boring. I feel like as a child on the map because of the high doors. Use srites instead of creating the man-hole cover like this:
http://img264.imageshack.us/img264/6662/csa420000jh1.png
tut how to create sprite:
http://www.fpsbanana.com/tools/42
Place the hostages in different rooms. Create a breakable rotating door, like:
http://twhl.co.za/mapvault_map.php?id=2086
Use tree models. Create light source and use texture lighting. Dont let the walls to be so flat, create columns, false windows,... Need to read more about mapping...keep going...

@redka:
thanks a lot for taking so much time reviewing my map. You are so right about the r_speeds.I'm trying to improve this- with the help of your links.
I don't quite understand what you mean with:

"The whole map is visible, see almost all the leaves see"

-do those leaves create too much polygons? Why is the whole Map visible? You can't see all the leaves at once.
By the way, how did you do this nice wireframe/textured- mix picture?

"There arent any furniture or stuff in it, which makes it a little bit boring"

This is exactly my main problem- I hoped to get some hints where to put stuff like boxes or else to hide and get cover. I just didn't want to put it in the wrong place, and thought I could get some helpful hints from pro gamers and tactical experts...

"I feel like as a child on the map because of the high doors"

You are right. The Proportions do not fit exactly to human scale.
And I'm going to use sprites..

"Place the hostages in different rooms. Create a breakable rotating door"

OK. will be done. I was searching for a tut on how to create a breakable rotating door- thanks again!

"Use tree models. Create light source and use texture lighting. Dont let the walls to be so flat, create columns, false windows,..."

This will be my next step! But first important thing for me is the tactical thing mentioned above..

why can't I edit my Post?

If it would be helpful, I could upload the map-file...

The wireframe picture was taken in game by writing gl_wireframe 2 in the console, only works in if you run your map like this:

http://twhl.co.za/tutorial.php?id=41

Reading visibility determination was very helpful for me at the begining to see how things work in compile.

http://collective.valve-erc.com/index.php?doc=1038660504-05211700

The gl_wireframe 2 option will highlight all the visible leaves that the enginee has to render at that moment. As from my pic you can see that almost all of your leaves highlighted. This is because of the layout of the map. The brush based entities dont block visibility, thats why the enginee has to render the leaves of the rooms when you are outside. Your doors are in bad places, replace them and use coridors to block vis. Plan the layout with this end in view.

Dont place boxes, they are ugly, be more creative, place a car model or columns or desks with computers or anything else then wood create boxes...
To know that they are in good places from the tatical view of point, I think this can be only figured out by testing the map, and planing the choke points at the begining.

You can easily see how tall the player by placing an info_playerstart.

I just now realised that you can run through the trees, it can be an exasperating camp positon and thus you can also go a place where the skybox is the border.