Custom Textures And Landscapes

i’m barley even a novice at hammer but i can do the basics, but i need help with importing custom textures and making landscape hills, i just dont know how, i know how to make ramps but that doesnt seem to be the right way (or the easiest) to make hills that dont look like pyramids. thanks to anyone who posts

Textures:
http://www.halfwit-2.com/?page=tutorials&category=12

Landscapes (Displacements):
http://www.halfwit-2.com/?page=tutorials&category=19

thanks