I play volleyball and I weight train almost everyday. What exercises/muscles should I work to improve my vertical and be more explosive?
Vertical jumps are all about power and explosiveness. The traditional slow, pick it up and put it down will improve some just due to the extra muscle mass and power, but you will be losing something if you don't cover the explosiveness. Additionally, if you aren't flexible in the hip flexor area (the muscles that drive the knee upwards), then you can inhibit the glutes and hip extension.
The main elements you want to look at are:
There are other stretches that can possibly contribute, such as calf stretches and hamstrings, but they will have less impact than the hip flexors will.
Plyometrics are probably the most misunderstood and abused forms of exercise (mostly due to the rise of crossfit and similar). Plyometrics are controlled and as explosive as you can make it, not repeated over and over. However, properly done, they can really contribute to explosiveness and power, and get you good increase on vertical height.
The basic ones that everyone knows are box jumps (jumping up to a box), lateral hops, broad jumps and scissor jumps. Again on stack (I have no affiliation, I just like a lot of their tutorials) there is a list of 10 plyometric exercises with video demonstrations.
CAUTION Please note the cautions at the bottom of the plyo exercises page about proper form, landing, etc. You can do a LOT of damage with improperly done plyo exercises. If you are jumping on to a box and your hips are below your knees, the box is too high. Additionally, I would personally scrub the barbell squat jumps. You are overloading the spine, and placing a lot of weight out away from the body, both of which can easily cause pretty severe injury. Given the vast range of exercises, you aren't really losing anything by taking that out.
Add the weight exercises into your normal routine, add plyometrics 1-2 times a week, stretch on a consistent basis, profit.
I ve been working out for along time and for about a year I did weight lifting with a local club where I learned the olympic weight lifting techniques the snatch and the clean and jerk.
The workout program was based on squats almost every day: front squat and back squat, and of course the other techniques of lifting.
I spent around 3 months just doing that and I ve noticed that my vertical leap and my explosiveness had increased as a result of stronger quads and back muscles.
I really recommend that you join a weight lifting club around where you live or just go to the gym and focus on your lower body doing more squats, leg extension and curls, deadlifts and calves raises.
I am a big fan of the NBA and one of the most explosive players in the league is Russell Westbrook, you can google the guy and see his dunks and speed.
Here is a video about Russell workout, you can follow it to and try for your self.
Hope that helps, good luck!