Make sure your concrete area is clean from dirt, debris and any weeds or other organic growth. If you need to clean the area, use a pressure washer to remove the dirt and debris. Use sponges to wipe up any excess dirt the pressure washer fails to clear.
Allow your concrete area to dry thoroughly. This can take some time, often a few days. Try to paint your concrete in the summer months when rain is unlikely.
Apply paintable concrete patch to any cracks and holes in the concrete. This gives you a smooth surface on which to paint and can help your concrete look new. After the patches have dried, sand them smooth with medium-grit sandpaper.
Apply concrete primer to the entire area. Always use a high quality concrete primer before applying paint or the paint will not adhere. Pour some primer into a paint tray and use a paint roller apply it in smooth, even coats. Like most painting, it's better to apply several light coats, as opposed to one thick coat. Depending on the condition of your concrete, two or three coats of primer should suffice. Allow the primer time to completely dry before applying the top coat.
Apply the top coat using concrete paint. Do not use regular paint or deck paint as it will not stand up to the abuse exterior concrete must take. Concrete-specific paint is available at all major hardware and paint stores. Just like the primer coat, apply light, even coats. Allow to dry thoroughly and your concrete should look good as new.