Step 1 – Go into your public_html folder
cd ~/public_html
Step 2 – Download Drupal using drush command
drush dl drupal
Note: If successful, drupal will be downloaded inside public_html/drupal-7.12 directory
Step 3 – Go inside drupal-7.12 folder
cd drupal-7.12
Step 4 – Move all files into public_html
mv * .* ..
Step 5 – Go to public_html directory, up one level
cd ..
Step 6 – Clean up, delete the empty folder
rm -rf drupal-7.12
Step 7 – Install drupal using drush
drush site-install --db-url=mysql://dbusername:password@localhost/dbname
Follow the instructions and answer yes if you ask to continue. After installation, take note of username/password given to you. Visit the browser and enjoy your new Drupal 7 website