Hello i have tried to model alot of things in blender and just recently i have been wanting to make a landscape. But i can’t find any help on that topic cause all tutorials (that i’ve seen) has been usin AT landscape which is for some reason not working with Blender 2.71 that i use.
Do anyone here have any tip on how i can use Blender to make a terrain / landscape?
Answers is very appreciated 
A few of options:
Just model it poly by poly like any other model (proportional editing may be useful)
Use a subdivided plane and use the sculpt tools
Use a subdivided plane and use a b+w terrain height texture with the displacement modifier
http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Landscape_Modeling_I:_Basic_Terrain
Here ANT Landscape works in 2.71 release candidate from buildbot - 169c95b. Do you have any error messages, can you allow addon in User Preferences?
http://www.pasteall.org/pic/73264