This is a Malzahar guide,i recomend maximizing the W first for extra damage and then to buy resistance and mana items for his problems,if you want to go jungle maximize E first for a more efectiveness jungleling.
Malzahar is a mid champion,so if you will go mid youl have to be caeful about your skill combo because of the very low ressistance and have to use the Q-W-E-R combo for a very high amount of damage.
For farming use the E for an more effectiveness combo and farming.
Always try to be carefull about your position on the lane because you may be ganked by other players if you are very good :D.