So my brother sent me this link, and at first my reaction was "..." but I ended up laughing so hard.
So check it out, if you aren't easily offended!
Why we should be eating horses instead of riding them - The Oatmeal
This is another good one.
How to Ride a Pony - The Oatmeal
And not horse related at all, but one I laughed at.
The 9 Types of Crappy Handshakes - The Oatmeal