Possibly the filesystem on the SD card has been corrupted, people seem to do this sometimes when they first get the pi by unplugging it indiscriminately. To check this with linux (a real system, a VM, or via a live CD), with the filesystem unmounted:
This will give you a clue as to whether the filesystem is okay, and hopefully also an opportunity to fix it. You may want to add the
-c switch to check for and quarantine bad blocks.
/dev/whatever2 refers to the second partition (the first partition is a small VFAT thing with the OS kernel in it, and is unlikely to be corrupted). So
/dev/whatever would be the whole card,
/dev/whatever1 would be the first (little VFAT) partition, and
/dev/whatever2 would be the primary ext2 partition.
If you are looking at logs, the one to look at is probably
/var/log/syslog, however, from the sounds of things very likely booting never reached the stage where the primary filesystem is (re)mounted read-write, so there won't be any information there.