Try booting into single user mode (hit '4' at the beastie text screen during the boot loader phase, right after your BIOS passes), and at the shell prompt run "fsck -y". Once that's done, exit the shell and your system will boot up normally. Let us know if you still have any errors after that point. Problems like free blk counts wrong in superblock are common after a system reboots uncleanly (power switch, power outage, etc).
Remember to always use the shutdown command to reboot or turn off your system so that it syncs the disks nicely.