cd ~ => move to the home directory  
mkdir directoryName => create dir
touch fileName => create file name
rm fileName => remove file 
rm -i fileName => remove file with conformation
rm -r folderName => remove folder with their content
rmdir folderName => remove folder with their content
pico fileName => open file in terminal editor
nano fileName => open file in terminal editor
open fileName => open file in default application
cat fileName => show the file in editor
pwd => file full path
screencapture -x -t jpg test.jpg => screen shot 

I will post other commands later...