At the end of a good calve workout, walking should be difficult. So should sitting and standing. You should just hurt.
Most pros perform higher reps with their calves than with any other muscle group--next to abs, of course. I think sets of 12 to 18 reps are the best, but then again I don't have perticularly huge calves do feel free to do what's best for you. Nasser El Sonbaty does have huge calves and he advocates 15 to 30 reps. You decide.
Nasser wrote a very informative article in Flex magazine about calve training in which he divulged the secrets of his 22 inch monsters. Much of the information here comes from that.
Essentially, it boils down to this: higher reps, full range of motion and peak contraction. Like bicep training, make sure you work the muscle through the entire range of motion, paying special attention to flex them at the top of the movement.
A lot of people don't realize that there are two independent muscles that contribute to calve size. One part can only be worked when the legs are bent 90 degrees, the other only when the legs are straight. It is for this reason that all the pros are sure to include at least one of each type of movement.
On to the exercises...
You'll need a seated calve raise machine to perform this movement. If your gym doesn't have one, you'll have to stick to other calve exercises. A thing to remember with all calve exercises is to concentrate on flexing the muscle on the way up. Go all the way up on your toes and come as far down as you can without allowing your feet to slip off the platforms.
Calves.
This exercise burns like crazy. I always do them first.
You can do this exercise on the Smith Machine, with a squat bar or on a machine especially designed for calve raises. I don't think it makes much difference, but if you use a Smith Machine or free weights, be sure to put a board under your toes to enable you to come farther down. As with all calve exercises, flex the muscle at the midpoint and go all the way up and all the way down. Be carefull not to bounce during this movement.
Calves.
If you do these on a smith machine and it bothers your shoulders and neck, try using a pad.
Perhaps the dumbbest looking of all calve exercises, this movement involves bending at the waist while keeping your legs straight and resting the weight on top of your upper butt/lower back. You really need a machine to do it. The same rules apply to this movement as the other two.
Calves.
One of the funniest things you'll ever see is when one bodybuilder straddles another one to get more weight on his back during this movement. When they start bouncing up and down you begin to wonder if it's worth it.
Calve raises can be performed on the leg press machine as well. Be sure to put the safety peg in the highest position for this movement so that you're not crushed by a falling carriage if your feet should slip.
Put your feet all the way at the bottom of the carriage so that your heels hang over the edge. Push the weight up until the carriage is on the balls of your feet. Lower it down all the way and repeat.
Calves.
Keep a very slight bend in your legs for this, if you allow your knees to lock you run the risk of having your legs buckle--this is really bad if you have three or four plates on each side.