The T-34 was a Soviet medium tank produced from 1940 to 1958. Although its armour and armament were surpassed by later tanks of the era, it has been often credited as the most effective, efficient and influential design of World War II. First produced at the KhPZ factory in Kharkov (Kharkiv, Ukraine), it was the mainstay of Soviet armoured forces throughout World War II, and widely exported afterward. It was the most-produced tank of the war, and the second most-produced tank of all time, after its successor, the T-54/55 series. In 1996, T-34 variants were still in service in at least twenty-seven countries.
This tank's biggest weakness is its armour, which, whilst sloped does not compare to that of a Panzer IV or even the Sherman. This tank is very mobile and has one of the most accurate guns in the game (the 57mm gun). Use your mobility to advance quickly to a good sniping position, exploiting the shallow profile of the T-34 (good stealth value) and forward position of the turret to hide most of your vulnerable rear. The high ROF of the 57mm gun, allows you to keep your enemies tracked and at range, whilst the good penetration means you will still do damage to them even when going up against higher tiers.
The T-34 is also an excellent scout tank and its high speed and mobility, paired with high ROF guns makes it ideal for exploiting loopholes in the enemy defenses and as an artillery hunter.
Get the 57mm gun as soon as possible.
Whilst this tank is a marked improvement on the A-20, it has low survivability, so cannot usually be played in the same aggressive fashion as the higher tier Russian tanks.