Screenshots of what you're doing.

Well it is my first map for Xonotic, did some mapping stuff in nexuiz already but had a break about 3 or 4 or 5 years i think ?! dont know anymore

... and because of the break i forgot a lot about the netradiant :/ and there are not many usefull tutorials on the internet for some actions ... :/

When it comes to netradiant you will figure everything out eventually (considering that you allready used it before), there are plenty of topics and threads spread around the internet that covers technical side of mapping. I will be more then happy to help you when Im done with exams and important stuff.

When it comes to level designing there is this tutorial:

http://www.reachingperfection.com/p/forge-lessons.html

It covers everything you need to know about making your map polished, balanced and great overall. I wish you good luck, friend with mapping.

PS: As a first map for Xonotic it looks very solid! I like lamp models you did there. Try to make everything less clean and well ordered, add some chaos to make it more realistic!