Have you tried this tutorial:
viewtopic.php?t=1491
If you are using windows, GTK Radiant 1.4 is your best bet. Unfortunately, Bubba's Arena website is no longer hosted by the Planet Bubba was the best for beginner mapping.
I highly recomend following that tutorial and compiling the included "dm_test1.map" <-- That map has all the entites needed for making a Smokin' Guns map.
Also, join our IRC channel if you would like help in real time. I understand English is not your first language, but we are understanding and there are some German speakers on the channel as well.
http://webchat.freenode.net/?channels=smokinguns