Step 1 :-
1] First of all create a shortcut of Counter-Strike in your Desktop if you don't have one.
2] Now, Right Click on the Shortcut and Click on Properties.
3] A Properties Dialog Box Pops Up.
4] Select the "Target" Area and add -dev to whatever is given inside the box. [Refer Screenie.]
5] Click on "Apply" button to apply settings before you quit.
Step 2 :-
1] Open Counter-Strike using the Shortcut.
2] Go To Console. [Usually the tilde (~) key on your keyboard opens it up.]
3] Type "map map name" [Without quotes.] in the console and Press Enter. Eg. map de_dust.
4] Now wait until the map loads.
5] By default you spawn in CT spawn.
6] Now open up console again. Type "noclip" [Without quotes.] and press enter.
7] Now you can roam freely around the map.
8] Just go to a good spot and take screenshots [Usually F5 button.]
There you go. It's a simple enough process. Step 1 once done does not need to repeated obviously. Enjoy duders!
Advantages are you can roam anywhere in the map and take screenshots. Also there are no "Black Bars" as in Spectator Mode. And you have no weapons in your hands, heck even the hands aren't visible
.This method can be used Condition Zero, The Specialists, and any other Half-Life 1 MOD.