home-Home directories for users
lost+found-Henry explained this one. It's where files go when fsck finds corrupted files.
root-Root user home directory
Here is the redundant stuff I was talking about earlier.
As you know cd is used to navigate the file system. That's it on cd. ls is more interesting.
ls lists files and directories.
ls -l gives you the permissions, links, date, group, and owner.
ls-a lists all files (means it lists hidden files too)
ls -i lists inode info
ls -lh shows "human-readable" output so that means things are in KB, MB etc...
Command here that I didn't know about is file.
file basically tells you what kind of file the file you're looking at is. So...
A text file might read out as text_file: ASCII text or if it's a binary it will tell you what kind of architecture it is.
Finally there's touch. touch can be used for different purposes the basic being creating a blank file like "touch blankfile". touch is also used to update the file's times. So if you wanted to change the file date of blankfile you would do touch -t yyyymmddhhmm blankfile, I believe that is self explanatory. One cool thing you can do is touch -r blankfile blankfile 2 where blankfile's time is copied to blankfile 2. Yup.