Captain's chair: Stabilize your upper body by gripping the hand holds and lightly pressing your lower back against the back pad. The starting position begins with you holding your body up with legs dangling below. Now slowly lift your knees in toward your chest. The motion should be controlled and deliberate as you bring the knees up and return them back to the starting position.
Don't worry, we're still talking snail's pace weight gain. Aim for one pound per week of lean muscle mass gains, though you may initially gain faster if you started out extremely lean or glycogen depleted. Start by adding 500 calories to your current daily intake, and maintain that intake until you plateau. If or when this happens, add another 250-500 calories and repeat.
One of the most misunderstood areas for new bodybuilders is nutrition. I talk to guys all the time that have no idea of their daily calorie intake, their daily protein intake, their carbohydrate intake. They have no idea of what types of foods they should be eating, or when they should be eating them. They don't know what supplements do what and what they should using. Let me refer readers to some of my other articles that detail these areas.