How is it having kids close to age?

Just had a baby girl on November 17th and hubby and I are ready to try for number 2! It took us 4 years to get pregnant with our baby girl so we want to start right away. So, if we get pregnant immediately that would be great. If not than we have a head start! How is it having babies close in age? We are hoping our daughter has a sibling close to her age!