Expand Raspbian Partition
From KlavoWiki
I usually expand the partition to 4GB form the default 3GB so I can re-image my installs. Once I've finished building my image I then expand the partition to maximum using the raspi-cofig utility.
I delete partition 2. making notice of where it starts. Create a new partition with the same starting block and finish at block 8533332
fdisk /dev/mmcblk0
resize2fs /dev/mmcblk0p2