Did you try this article? It is a tutorial for moving a wordpress blog from a Linode VPS to a DO VPS (the opposite of what you're asking), but contains many steps and general tips that you will find useful. https://www.digitalocean.com/community/tutorials/migrate-you...
In general terms, you'll be looking at something like this: boot a fresh VM at Linode, apply updates, and install all your needed packages. Stop services on both hosts. Copy the necessary data/config files to the destination host, using a tool such as scp or rsync. Set permissions/ownership on destination files if needed. Start services on the destination host, test everything, reconfigure dns, and you're all set.
FWIW, I've been a happy linode user for 5+ years. I have nothing against DO, I've just never had cause to use them yet.
Incidentally, you mentioned in your blog that you tried a range of shared-hosting providers (HostGator, Bluehost, iPage...) finding them all unsatisfactory, before deciding to move to a dedicated VPS. You may or may not be aware that all three of those providers (and many more) are actually owned by one parent company, http://en.wikipedia.org/wiki/Endurance_International_Group (i.e.: by trying a set of commonly-owned companies you may not have ended up surveying a particularly diverse cross-section of the market).