This adorable but simple set of patterns would be a great start for knitting garments (tiny humans mean a lot less knitting!). For more advanced knitters, these patterns are super easy to personalise: you could add applique letters using crochet or simple colourwork stripes.
These patterns are knitted in King Cole Cherished DK (the solid colour) and King Cole Cherish DK (the variegated). This is a super soft acrylic blend made just for babies. You could try King Cole Cottonsoft DK for a lovely summer knit.