My blazer just started shaking when I first take off and there is a weird noise coming from the driver side rear tire. The shaking stops once I get up to cruising speeds. HELP PLEASE lol

 

You may have lost one or more of the balancing weights on your wheel, or you could have mud or ice caked on the inside of your wheel throwing off your balance.

 

Check your rear driveshaft 'U' joints.

You may have broken a Cap. When it spins fast enough they tend to center themselves and stop vibrating. You cannot check the Jints with the car in Park and pressure on the shaft. Chock the wheels. put it in Neutral and rotate the shaft and look for movement in the Joint