Check for powr:Take a test light or even an old tailight bulb with two wires solder to it and test to see which wire is hot(red) and ground (black).
Don't believe in labels, like Rob said if you hook it up backwards and turn the radio on it will pop the polarity diode inside the radio.
Power cord: Go to any truck stop/cb shop and get the right power cord for it, solder and shrink wrap any connections. electrical tape won't last in the cab, it gets hot and the glue comes apart.
Good coax: Get some good 8x, clear or gray it doesn't matter, see if you can find the kind with the soldered on ends(pl259's) versus the crimped on ones. The factory stuff that they run thru the trucks is junk.
Check and set swr: You can go two ways here, get a small swr meter, radio shack and workman make them for about $25 dollars and a 3 foot jumper. There is plenty of info on how to set/tune your antenna.
Or if you have a trusted cb shop you can stop by and have them set it up.
I would buy the meter that way you have it and if you ever suspect a problem you can test you system.
This is the most important step and oftened overlooked,The Mount, it's not about looking cool, you want the tip of the antenna near the top of the air shield or trailer. You see guys buy antennas that are to long or the mount on the truck is to low, yeah it will work, but the signal if reflecting off the side of the truck, look at other trucks like yours or online to find a mount that will do it.
This will get you talking, hope this helped.