`where are my cs textures and where do i put new ones?

[comradpoplin1]

lo all i have just started using hammer and im progressing rather quickly i have started building a cs map but i have noticed most of the textures and stuff are hl2 textures ive looked through the browse window in hammer and cant seem to find much cs:S stuff oh and where do i put new textures when i get them?
and one more thing ive tested the parts of the map i have done but how do i add a buy zone?
all ya help would be appreaciated thnx