Condition Zero maps are just like counter-strike maps - needing only an info_player_start and info_player_deathmatch entity. The only difference is in how you use it.
In order to use a custom map in Condition Zero, make sure you place the map in the "condition zeroczeromaps" folder as opposed to the "condition zerocstrikemaps" folder. When you first run the map, the map will restart 2-3 times before it will start running normally. This is because Condition Zero must create the bot NAV file first. After it has done that, the NAV file is stored with the map in the "condition zeroczeromaps" folder.
If you ever change a map (recompile it), make sure you delete the previously CZ created NAV file before running the map (so that CZ can generate a new one).