What is this Weed?
This looks to be chickweed. It is young yet so it's possibly hairy bittercress. Both are winter annuals, germinating in later summer/fall and then wintering over to bloom in spring. Hand pulling or using a pre-emergent to prevent germination are the usual suggestions, but there is more info here:
Hairy bittercress looks will grow into a frilly-looking basil rosette until it blooms in spring. See here: http://extension.umd.edu/hgic/hairy-bittercress