How can I tell my baby I love him? Or rather, what should I do to make him feel loved?

This depends on the baby age. if he is just couple of months old, he may not recognize people yet. All he needs is attention - stay with him, sing lullaby to him, make faces and cheer him. He feels loved. once he is grow up, may be nearing his 1st birthday, he will recognize you. He will cling to you. He needs your hugs when he slips while crawling or falls while trying to stand up or when frightened for a thunder sound. Hugs and kisses smoothens him. Playing a peek-a-boo or cheering him up keeps your bonding. The best satisfying bonding is feeding your baby. The more bonding you have, the more blessed and loved he feels.