As a basketball player, how often do I need to do strength training?

During the off-season you should perform strength training 3-4 days/week.  During the in-season you should perform 2-3 strength training sessions/week.

Tips:
1. Start slow
2. Be progressive
3. 3 month training cycle
    a. Stabilization (2-3 sets of 12-15 total body exericises focusing on muscle endurance)
    b. Strength (3-4 sets of 1-12 repetitions focusing on strength)
    c. Power (1-3 sets of 1-10 reps focusing on explosion and speed of movement)
4. Utilize an integrated training model that incorporates flexibility, core, balance, speed, agility, reaction, quickness, strength, and cardio to create maximum benefits

NOTE:  I highly recommend utilizing a certified sports performance coach to help you create the optimum performance training program to help you maximize your performance and decrease your chance of injury

Experts recommend that you strength train 2-3 days per week with a minimum of 48 hours rest between sessions for similar muscle groups.  Further, it is not recommended that you perform more than 6 sets per muscle group in a training session.  Generally, a total body resistance training routine done 2 -3 times a week is sufficient to make gains.  Fewer than 2 sessions per week will not result in continual progress. The volume of exercise you perform and the amount of rest and recovery you get between sessions is very important to your performance.  You should avoid over training because it can predispose you to injury.  Performing too much work can end up just overtaxing your body and be a huge waste of time.