I got Drush working on my site the other day. It was pretty cool doing the Drupal 7.37 from a command line. No deleting folders out of FTP and dragging them back in again. One thing that I had to watch out for was the drush update command wanted to overwrite my .htaccess and robots.txt along with everything else. It also pushes up all the junk .txt files in the distro. I usually omit those.
1. Get SSH access to my host. Bluehost wants you to call them to verify your account. I don't like to be on the phone so I put this off for awhile.
2. Install Composer
3. Figure out how to get Drush to use a high enough version of PHP. For some reason the site is served up with php 5.4 but the shell was in 5.2.
4. Install Drush
5. Fix some things in bashrc specifically pathing out composer and drush aliases so they can use php5.4
alias composer='/ramdisk/php/54/bin/php54-cli ~/common/composer.phar' >> ~/.bashrc