When choosing developmental baby toys for newborns in the 3-6 month old category remember they are starting to notice the sensation of touch more, and are also beginning to explore their gross motor skills more and just starting to develop their fine motor skills. Just be aware, that everything will get placed straight into the baby's mouth. This is a natural developmental process and for this reason i steer clear of teddy bears for this age group because I don't like the idea of the baby sucking off any of the hair. Toys which are useful for this age group include:
Musical Toys - Bells and maracas are excellent toys for this age group and will last well into preschool age as a toy that will be used again and again. Helping teach rhythm and music, but also that the baby can create sounds and control their world to an extent, these toys are excellent. They are also easy enough for the baby to hold and help encourage gross motor development while being used like a rattle.
Activity Mats - Like the younger age group activity mats are a great way to encourage the baby to kick and bat at the mobile that hangs above them. The 3-6 month old will also be better at tracking the movement of the toys on the mobile with their eyes by this stage.
Toys with Texture are perfect toys for helping the baby to develop some fine motor control. The baby will be interested in feeling all the different textures, from smooth to furry, bumpy to squishy, and this will encourage the baby to touch the toys more.
Toys which make a sound when touched or moved. This doesn't have to mean the toy has a battery, At this stage babies love toys which have cellophane inside them which makes a noise when being squashed. They also love toys with bells in them, but flashing lights and sounds are always great for a distraction too!