Share some my experience I got from taking my 5-month baby. Normally, infant doesn't move very fast. She/he will not move from place to place. (for older kids who can walk, toddlers, that's different story)
Use a tripod and shuttle release cable or remote control. The advantages are you can free you hand and can talk with baby, and avoid hand shake as well. Set ISO as high enough and noise you can accept (depends on what digital camera you use. if film camera, use high ISO film.) so that the shuttle speed can be higher. I often use 28-70 zoom lens and set aperture as F5.6-8. Use manual focus and focus on her/his eyes if use tripod. Don't compose too tight in viewfinder, zoom out little bit, to avoid baby move out picture. Then you can talk with baby, and control the camera with remote or cable in good moment.
Tips:
1.always focus on eyes.
2.avoid busy background.
3.avoid cut baby's hands or feet.
4.use continue shoot mode