Late infancy is not too soon to discipline your child, though, of course, you cannot punish a baby. Discipline at this age involves helping your child understand limitations -- both his own and yours.
At about 10 months of age, your baby begins to understand that she can do things that make you frown -- and she may delight in achieving your attention this way. This isn't any kind of manipulation or power play on your baby's part. Instead it reflects her growing awareness that she can have an impact on her environment, a healthy realization. Even so, you will need to set boundaries for her now if she persists in behavior you want her to stop. A common type of behavior for a baby this age is to turn on the TV or radio, and, if allowed, she might do it over and over. If this happens, don't over-react by becoming angry or scolding. Simply say no, and take your baby away from the source of the behavior. Follow up by distracting her with a new activity. When she heads for the TV buttons again, respond in the same way. By being consistent and not overly reactive, you accomplish two things: You let her know that a behavior is not allowed, and you reinforce your position as teacher and helper without becoming her adversary.
A few babies, as they approach their first birthday, also attempt a temper tantrum of sorts. They will lie on the floor and scream when they are frustrated about something. Although you'll probably be alarmed by such a reaction, it's best to ignore the behavior, and, after the storm passes, hold your baby and calm her with quiet talk. By acting unimpressed, you'll discourage any further tantrums for at least a number of months more.