Question about steering shake/wobble

First post so I might as well just jump right in.

I just bought a 2005 Tacoma Dbl Cab SR5 with 172k miles. Truck appears to be in great shape but now that I have been driving it a little more I am noticing steering shake or wobble. It seems like excessive slack to me but not sure where to start looking. I get up to about 55 mph and steering wobbles a little but I notice this even driving 5 mph in my back field going over bumps or what not. Where do I start looking to tighten this issue up?

 

This was one of my first topics when i signed up to TW as well. Basically people will tell you to use the search function, there are many different things it could be and i suggest searching multiple threads before jumping to anyones conclusion