Steering a boat with a wheel is similar to driving a car. Steering a boat is more difficult as there is a time delay between your action and the boat responding. In addition, it is harder to know the setting for straight ahead.
Use small movements on the steering wheel is best to enable you to get the feel of the boat.
When you turn the steering wheel of your car, the front wheels turn, causing the front end of the car to begin to turn. The rear of the car follows (unless you are in a skid). On a boat when you turn the wheel on your boat, the stern (back) starts to swing in a large arc, thus changing the direction of the boat.
You should make sure that you have enough room for your boat's stern to swing.
Using a tiller to steer a boat is straight forward. You just need to remember that pushing to the right will make the boat head left and vice versa. The key is to make planned movements as the boat will take a few seconds to respond.
Your boat pivots from a point about halfway along its length. That means you need to watch out for the front and the back. If you line up the front only and then try to turn into a narrow gap you may hit the side with the back of your boat.